Estimate your puppy's future adult weight based on breed and current measurements.
Puppy Growth Predictor
Small (e.g., Chihuahua, Yorkshire Terrier)
Medium (e.g., Beagle, Border Collie)
Large (e.g., Labrador Retriever, German Shepherd)
Giant (e.g., Great Dane, Mastiff)
Select the general size group of your puppy's breed.
Enter your puppy's current weight in kilograms.
Enter your puppy's current age in weeks.
Enter the typical adult weight of this breed, or a specific breed's 12-week weight if known.
Estimated Adult Weight
— kg
Estimated Weight Factor: —
Typical Adult Weight Range: — kg
Reference Adult Weight: — kg
Formula: Adult Weight ≈ (Current Weight / Current Age in Weeks) * (Reference Adult Weight / 12 weeks) OR Adult Weight ≈ Current Weight * (12 / Current Age in Weeks) * Weight Factor. The primary method uses a breed-specific factor, adjusted by current age and weight.
Growth Projection Chart
Estimated puppy growth curve based on breed group and inputs.
Typical Adult Weight Ranges by Breed Group
Breed Group
Typical Adult Weight (kg)
Notes
What is a Puppy Adult Weight Calculator by Breed?
A puppy adult weight calculator by breed is a tool designed to help pet owners and breeders estimate how large a puppy will grow to be when it reaches adulthood. Unlike generic weight calculators, this tool takes into account breed-specific growth patterns, which vary significantly from a tiny teacup Poodle to a giant Great Dane. It uses your puppy's current age and weight, combined with breed information, to project its future size.
Who should use it?
New puppy owners who want to prepare for their dog's future size (e.g., for housing, grooming, or training needs).
Breeders who need to track the growth of litters and ensure puppies are developing within expected parameters.
Veterinarians and vet techs as a quick reference tool.
Anyone curious about how much their mixed-breed puppy might grow, by using the closest matching breed group.
Common Misconceptions:
Myth: All puppies of the same breed grow at the exact same rate. Reality: Genetics, diet, health, and environment play a role, leading to variations even within a breed.
Myth: A puppy's adult weight is directly proportional to its current weight. Reality: Growth curves are not linear; puppies grow fastest in their early months and then slow down.
Myth: The calculator guarantees an exact final weight. Reality: It provides an educated estimate based on averages and typical growth patterns.
Puppy Adult Weight Calculator by Breed Formula and Mathematical Explanation
The estimation of a puppy's adult weight involves several factors, primarily its current age, current weight, and a breed-specific reference point. While precise formulas can be complex and proprietary, a common approach uses a multiplier or growth factor derived from typical breed growth rates.
A simplified, widely used estimation method is:
Adult Weight ≈ Current Weight * (12 / Current Age in Weeks) * Breed Factor
Where:
Current Weight (kg): The puppy's weight at the time of measurement.
Current Age in Weeks: The puppy's age in weeks. A common reference point is 12 weeks, as puppies are typically well into their growth phase by then.
12: A constant representing the reference age in weeks.
Breed Factor: A multiplier that adjusts the projection based on the typical growth rate of the puppy's breed group. This factor is often derived from the expected adult weight at 12 weeks or a general growth curve. For example, a smaller breed might have a lower factor than a larger breed.
A more refined calculation integrated into this calculator considers the relationship between current weight, current age, and a reference adult weight (often the midpoint of the breed's typical adult weight range or a specific value for a 12-week-old puppy). The core idea is to understand how the puppy's current size relates to its expected adult size at different developmental stages.
Variable Explanations:
The calculator uses the following variables:
Variable
Meaning
Unit
Typical Range
Current Weight
The puppy's current body mass.
kg
0.1 – 50+ kg (depends on puppy age/breed)
Current Age
The puppy's age in weeks.
Weeks
1 – 52+ weeks
Weight at 12 Weeks
The breed's typical weight at 12 weeks OR the breed's typical adult weight (used as a reference).
kg
0.5 – 40+ kg (depends on breed)
Breed Group
Categorization of the breed based on expected adult size.
Category
Small, Medium, Large, Giant
Estimated Adult Weight
The projected weight of the dog when fully grown.
kg
Highly variable, depends on breed
Reference Adult Weight
A standard weight for the breed group used in calculation.
kg
Variable, based on breed group average
Weight Factor
A multiplier indicating how mature the puppy is relative to its adult size at a given age.
Unitless
0.1 – 1.0+
Practical Examples (Real-World Use Cases)
Understanding how the puppy adult weight calculator by breed works in practice can be very helpful. Here are a couple of scenarios:
Example 1: Medium Breed Puppy
Scenario: Sarah just adopted a 10-week-old Border Collie puppy named Max. Max currently weighs 4.5 kg. The typical adult weight for a Border Collie is around 18-20 kg.
Inputs:
Breed Group: Medium
Current Weight: 4.5 kg
Current Age: 10 weeks
Weight at 12 Weeks (using midpoint of adult range as reference): 19 kg
Calculator Output:
Estimated Adult Weight: Approximately 19 kg
Estimated Weight Factor: ~0.24 (indicating Max is about 24% of his adult weight)
Typical Adult Weight Range: 16 – 22 kg (based on breed standard)
Reference Adult Weight: 19 kg
Interpretation: Based on his current growth rate and breed, Max is projected to reach an adult weight of around 19 kg. This aligns well with the typical adult weight range for Border Collies, suggesting he is growing at a healthy pace. Sarah can use this information to plan for food portions and ensure she has adequate space for a dog of this size.
Example 2: Large Breed Puppy
Scenario: Mark has a 16-week-old Labrador Retriever puppy, Bella, who weighs 15 kg. Adult Labradors typically range from 25 to 36 kg.
Inputs:
Breed Group: Large
Current Weight: 15 kg
Current Age: 16 weeks
Weight at 12 Weeks (using midpoint of adult range as reference): 30.5 kg
Calculator Output:
Estimated Adult Weight: Approximately 28.5 kg
Estimated Weight Factor: ~0.49 (indicating Bella is about 49% of her adult weight)
Typical Adult Weight Range: 25 – 36 kg (based on breed standard)
Reference Adult Weight: 30.5 kg
Interpretation: Bella is estimated to reach an adult weight of about 28.5 kg. This falls comfortably within the expected adult weight range for Labrador Retrievers. Mark can be reassured that Bella is developing appropriately. This projection helps him mentally prepare for the size of his adult dog and adjust his expectations for training and exercise needs.
How to Use This Puppy Adult Weight Calculator by Breed
Using our puppy adult weight calculator by breed is straightforward and takes just a few moments. Follow these steps to get an estimate for your furry friend:
Select Breed Group: First, choose the general size category (Small, Medium, Large, Giant) that best matches your puppy's breed. If you have a mixed breed, select the group that best represents the largest breed in their lineage or the overall expected size.
Enter Current Weight: Accurately weigh your puppy and enter the value in kilograms (kg) into the "Current Weight (kg)" field. Ensure you use a reliable scale.
Enter Current Age: Input your puppy's current age in weeks into the "Current Age (weeks)" field. Precision here is important as growth rates change rapidly.
Enter Reference Weight: In the "Weight at 12 Weeks" field, enter the typical adult weight for your puppy's specific breed, or a known weight for that breed at 12 weeks old. You can often find this information from breed club websites, veterinary resources, or by consulting your breeder. For mixed breeds, estimate based on the largest parent breed or average expected adult size. This acts as the benchmark for comparison.
View Results: Once all fields are filled, the calculator will automatically display:
Estimated Adult Weight: Your puppy's projected full-grown weight in kilograms.
Estimated Weight Factor: A general indicator of how much growth is remaining.
Typical Adult Weight Range: The common weight range for the selected breed group.
Reference Adult Weight: The benchmark weight you entered.
Interpret and Decide: Compare the Estimated Adult Weight to the Typical Adult Weight Range. If the estimate falls within the range, your puppy is likely on track. If it's significantly higher or lower, consider factors like diet, genetics, or consult your veterinarian.
Use Advanced Features:
Chart: Visualize the projected growth curve.
Table: Refer to typical weight ranges for different breed groups.
Copy Results: Save or share your calculated estimates easily.
Reset: Start over with fresh inputs if needed.
Remember, this calculator provides an estimate. Individual growth can vary. For personalized advice, always consult your veterinarian or a professional breeder.
Key Factors That Affect Puppy Adult Weight Results
While the puppy adult weight calculator by breed uses standard formulas, several crucial factors can influence a puppy's actual adult weight, causing variations from the estimate. Understanding these elements provides a more complete picture of your dog's development:
Genetics: This is the most significant factor. Even within the same breed, genetic predispositions for size can vary. If your puppy's parents were on the larger or smaller end of the breed's standard, your puppy is likely to follow suit. Mixed breeds have even more genetic variability.
Nutrition and Diet: A balanced, high-quality diet appropriate for the puppy's age, size, and activity level is critical. Overfeeding can lead to obesity and potentially exceeding the healthy adult weight range, while underfeeding can stunt growth. Consistent, appropriate nutrition is key for reaching genetic potential healthily.
Health and Medical Conditions: Certain health issues, such as parasites, chronic illnesses, hormonal imbalances (like hypothyroidism), or metabolic disorders, can significantly impact a puppy's growth rate and final size. Regular veterinary check-ups are essential for early detection and management.
Spaying/Neutering: Studies suggest that early spaying or neutering *might* influence growth plate closure, potentially leading to slightly taller and sometimes heavier dogs compared to intact counterparts. The exact impact can vary by breed and individual.
Activity Level and Exercise: While exercise is vital for muscle development and overall health, excessive high-impact exercise in very young puppies can potentially harm developing joints. Appropriate exercise helps build lean muscle mass, contributing to a healthy body composition rather than just weight.
Environment and Stress: A stable, low-stress environment promotes healthy development. Chronic stress can affect a puppy's overall well-being and potentially its growth rate. Access to clean water, appropriate shelter, and social interaction are also important environmental factors.
Deworming and Parasite Control: Internal parasites can rob a puppy of essential nutrients, directly hindering growth and leading to a lower adult weight than genetically predicted. Regular deworming is crucial for puppies.
By considering these factors alongside the calculator's estimate, owners can better support their puppy's healthy development and manage expectations for their dog's future size.
Frequently Asked Questions (FAQ)
Q1: How accurate is this puppy adult weight calculator by breed?
A: The calculator provides an educated estimate based on breed averages and common growth patterns. Accuracy can vary, especially for mixed breeds or puppies with unique genetics. It's a helpful guide, not a definitive prediction.
Q2: My puppy is a mixed breed. How should I use the calculator?
A: For mixed breeds, select the breed group that best represents the largest parent breed or the expected adult size. You can also try inputting characteristics of different breeds if you have an idea of the lineage, and compare the results.
Q3: What is the best way to measure my puppy's weight?
A: The most accurate way is using a pet scale, often available at veterinary clinics or larger pet stores. Alternatively, weigh yourself, then weigh yourself holding the puppy, and subtract your weight from the combined weight. Ensure the puppy is calm and still.
Q4: My puppy seems to be growing much faster/slower than the estimate. Should I worry?
A: Some variation is normal. However, if you notice extreme differences, consult your veterinarian. Rapid growth spurts or prolonged periods of slow growth can sometimes indicate underlying health or nutritional issues.
Q5: Does the breed group accurately reflect all breeds?
A: Breed groups are a simplification. Within each group, there's a range of sizes. For highly specific breeds within a group, consulting breed-specific resources for adult weight estimates might offer more precision.
Q6: How does diet affect puppy growth?
A: Diet is crucial. Puppies need a balanced diet formulated for their life stage. Overfeeding can lead to rapid weight gain and potential skeletal issues, while poor nutrition can stunt growth. Always feed a high-quality puppy food appropriate for their expected adult size.
Q7: At what age do puppies stop growing?
A: This varies greatly by breed size. Small breeds typically reach their adult size around 6-9 months. Medium breeds may continue growing until 12-15 months. Large and giant breeds can take 18-24 months or even longer to reach their full size and mature.
Q8: Should I use the calculator to determine feeding amounts?
A: While the calculator helps estimate adult size, which informs long-term feeding strategy, it's best to follow the feeding guidelines on your chosen puppy food packaging, adjusted based on your puppy's current condition and your veterinarian's recommendations. Your vet is the best resource for precise dietary advice.
var breedData = {
small: { referenceWeight: 5, name: "Small Breeds" },
medium: { referenceWeight: 15, name: "Medium Breeds" },
large: { referenceWeight: 25, name: "Large Breeds" },
giant: { referenceWeight: 45, name: "Giant Breeds" }
};
function updateBreedOptions() {
var breedGroupSelect = document.getElementById('breedGroup');
var selectedGroupKey = breedGroupSelect.value;
var referenceWeightInput = document.getElementById('weightAt12Weeks');
var referenceWeightLabel = document.querySelector('label[for="weightAt12Weeks"]');
var helperTextElement = referenceWeightInput.nextElementSibling;
if (breedData[selectedGroupKey]) {
var groupInfo = breedData[selectedGroupKey];
referenceWeightLabel.textContent = "Reference Adult Weight for " + groupInfo.name + " (kg)";
referenceWeightInput.placeholder = "e.g., " + groupInfo.referenceWeight + " (for " + groupInfo.name + ")";
referenceWeightInput.value = ""; // Clear previous value
calculateWeight(); // Recalculate if needed
populateBreedTable(); // Update table
}
}
function populateBreedTable() {
var tableBody = document.querySelector('#breedWeightTable tbody');
tableBody.innerHTML = "; // Clear existing rows
var tableData = [
{ group: "Small", range: "1-10 kg", notes: "e.g., Chihuahua, Yorkshire Terrier, Pomeranian" },
{ group: "Medium", range: "10-25 kg", notes: "e.g., Beagle, Border Collie, Cocker Spaniel" },
{ group: "Large", range: "25-45 kg", notes: "e.g., Labrador Retriever, German Shepherd, Golden Retriever" },
{ group: "Giant", range: "45+ kg", notes: "e.g., Great Dane, Mastiff, Saint Bernard" }
];
tableData.forEach(function(item) {
var row = tableBody.insertRow();
var cellGroup = row.insertCell(0);
var cellRange = row.insertCell(1);
var cellNotes = row.insertCell(2);
cellGroup.textContent = item.group;
cellRange.textContent = item.range;
cellNotes.textContent = item.notes;
});
}
function validateInput(id, min, max, allowEmpty = false) {
var element = document.getElementById(id);
var errorElement = document.getElementById(id + 'Error');
var value = parseFloat(element.value);
var isValid = true;
errorElement.textContent = ";
errorElement.classList.remove('visible');
element.style.borderColor = '#ddd'; // Reset border color
if (element.value.trim() === " && !allowEmpty) {
errorElement.textContent = 'This field is required.';
isValid = false;
} else if (element.value.trim() !== ") {
if (isNaN(value)) {
errorElement.textContent = 'Please enter a valid number.';
isValid = false;
} else {
if (!allowEmpty && value <= 0) {
errorElement.textContent = 'Value must be positive.';
isValid = false;
} else if (min !== null && value max) {
errorElement.textContent = 'Value cannot be greater than ' + max + '.';
isValid = false;
}
}
}
if (!isValid) {
errorElement.classList.add('visible');
element.style.borderColor = '#dc3545';
}
return isValid;
}
function calculateWeight() {
var currentWeightKg = parseFloat(document.getElementById('currentWeightKg').value);
var currentAgeWeeks = parseFloat(document.getElementById('currentAgeWeeks').value);
var weightAt12WeeksRef = parseFloat(document.getElementById('weightAt12Weeks').value); // This is our reference point (e.g., expected adult weight)
var breedGroup = document.getElementById('breedGroup').value;
var primaryResultElement = document.getElementById('primaryResult');
var weightFactorElement = document.getElementById('weightFactor');
var adultRangeElement = document.getElementById('adultRange');
var referenceAdultWeightElement = document.getElementById('referenceAdultWeight');
// Resetting display
primaryResultElement.textContent = '– kg';
weightFactorElement.textContent = '–';
adultRangeElement.textContent = '– kg';
referenceAdultWeightElement.textContent = '– kg';
chart.destroy(); // Destroy existing chart
initChart(); // Reinitialize chart
var isValid = true;
if (!validateInput('currentWeightKg', 0.1)) isValid = false;
if (!validateInput('currentAgeWeeks', 1, 100)) isValid = false; // Max age approx 2 years
if (!validateInput('weightAt12Weeks', 0.5)) isValid = false; // Min adult weight
if (!isValid) {
return;
}
// — Calculation Logic —
var breedInfo = breedData[breedGroup];
var referenceAdultWeight = weightAt12WeeksRef; // Use the user's input as the reference adult weight for this calculation
referenceAdultWeightElement.textContent = referenceAdultWeight.toFixed(1) + ' kg';
// Calculate a rough weight factor based on maturity
// This factor estimates how far along the puppy is towards its adult weight
// A common simplification is to assume a puppy at 12 weeks is ~25-30% of its adult weight.
// More advanced models exist, but this provides a starting point.
var maturityFactor = (currentAgeWeeks 52) maturityFactor = 1.0; // Cap for very old puppies
var projectedWeight = (currentWeightKg / currentAgeWeeks) * (referenceAdultWeight / 12);
// Ensure the projected weight is not less than current weight
if (projectedWeight k = 12 / 0.25 = 48.
// Let's test this 'k' value.
var k = 48; // General multiplier for larger breeds
if (breedGroup === 'small') k = 30;
else if (breedGroup === 'medium') k = 40;
else if (breedGroup === 'giant') k = 60;
var estimatedAdultWeight = (currentWeightKg / currentAgeWeeks) * k;
// Refine based on the provided 'weightAt12Weeks' which is treated as Reference Adult Weight.
// Let's adjust the multiplier 'k' to better reflect the 'weightAt12Weeks' input,
// assuming this input represents the expected adult weight.
// If puppy is 12 weeks, and weightAt12Weeks is adult weight, then current weight IS reference weight.
// If puppy is younger than 12 weeks, and weightAt12Weeks is adult weight, puppy should be lighter.
// If puppy is older than 12 weeks, and weightAt12Weeks is adult weight, puppy should be heavier.
// A more robust approach:
// Estimate growth factor: How much heavier will the puppy get?
// Assume at `currentAgeWeeks`, the puppy is `currentWeightKg`.
// Assume at `targetAgeWeeks` (e.g., 52 weeks), the puppy will be `estimatedAdultWeight`.
// The ratio `estimatedAdultWeight / currentWeightKg` should roughly correspond to
// the ratio `targetAgeWeeks / currentAgeWeeks` scaled by breed maturation.
// Let's use a common heuristic: Puppy reaches X% of adult weight by Y weeks.
// For medium/large breeds, 50% by ~16-20 weeks is common.
// Let's simplify: if current age 12 weeks, adjust.
// Use the 'weightAt12Weeks' as the *reference point for adult weight*.
// The calculator needs to estimate *final* adult weight.
// If the user inputs the expected ADULT weight into 'weightAt12Weeks', then the calculation is:
// Projected Adult Weight = Current Weight * (Expected Adult Weight / Current Weight at Expected Age)
// We don't know Current Weight at Expected Age directly, but we know current age.
// Let's use a formula that scales based on the ratio of the `weightAt12Weeks` reference to the typical weight for that breed group at the current age.
// A simpler, common approximation:
// Adult Weight ≈ Current Weight * (Reference Adult Weight / Current Weight at Reference Age)
// If we assume Reference Adult Weight is the user's input `weightAt12Weeks`, and
// we assume that at 12 weeks, a puppy weighs roughly 25% of its adult weight (for large breeds).
// So, weight at 12 weeks ≈ 0.25 * `weightAt12Weeks`.
// Then, `estimatedAdultWeight` ≈ `currentWeightKg` * (`weightAt12Weeks` / (0.25 * `weightAt12Weeks`)) — This is flawed.
// Let's rethink the core calculation:
// The goal is to predict the final weight.
// A popular method: Double the puppy's weight at 12 weeks to estimate adult weight.
// Or, for large breeds: Weight at 12 months = Weight at 16 weeks * 2.
// Or, simpler: Adult Weight = Current Weight * (Reference Adult Weight / Weight at Current Age)
// **Revised Calculation Approach:**
// Treat `weightAt12Weeks` as the approximate adult weight for the breed.
// Estimate how mature the puppy is.
var estimatedAdultWeightFinal;
var referenceWeightForGroup = breedData[breedGroup].referenceWeight; // e.g., 25kg for large
// If puppy is young (e.g., 24 weeks), it's closer to adult weight.
if (currentAgeWeeks < 16) {
// Projecting forward. Assume a growth factor.
// A common heuristic: Puppy reaches approx 50% of adult weight by 16 weeks.
// So, Adult Weight ≈ Current Weight * (16 / Current Age) * (Weight at 16 weeks / Reference Adult Weight)
// Let's use the user input `weightAt12Weeks` as the primary target.
// We can estimate the current "stage" relative to the target adult weight.
// Estimated Adult Weight ≈ `currentWeightKg` * ( `weightAt12Weeks` / (weight at current age based on reference) )
// Simplest approach: Treat `weightAt12Weeks` as the user's best guess for the breed's adult weight.
// Then, estimate the puppy's current maturity.
// If puppy is 8 weeks, and adult is 20kg, puppy might be ~10kg.
// If puppy is 12 weeks, puppy might be ~15kg.
// If puppy is 16 weeks, puppy might be ~18kg.
// Formula: Adult Weight = Current Weight * (Reference Adult Weight / Current Weight at this Age)
// We need to estimate "Current Weight at this Age" based on the Reference Adult Weight.
// Let's use a simplified maturity curve:
var weightAtCurrentAgeEstimate;
if (currentAgeWeeks <= 12) {
weightAtCurrentAgeEstimate = weightAt12WeeksRef * (currentAgeWeeks / 12) * 0.8; // Puppy is lighter than linearly extrapolated
} else if (currentAgeWeeks <= 24) {
// Puppy is past the rapid growth phase, approaching maturity.
// Estimate linearly between 12 weeks and 24 weeks towards adult weight.
var factorAt12Weeks = 0.25; // Assume 25% of adult weight at 12 weeks
var factorAt24Weeks = 0.75; // Assume 75% of adult weight at 24 weeks
var currentFactor = factorAt12Weeks + (factorAt24Weeks – factorAt12Weeks) * ((currentAgeWeeks – 12) / (24 – 12));
weightAtCurrentAgeEstimate = weightAt12WeeksRef * currentFactor;
} else {
// Puppy is older, growth is slowing significantly. Assume it's close to adult weight.
weightAtCurrentAgeEstimate = weightAt12WeeksRef * 0.95; // Approaching final weight
}
// Ensure weightAtCurrentAgeEstimate is not zero or negative
if (weightAtCurrentAgeEstimate estimatedAdultWeightFinal * 0.8) {
estimatedAdultWeightFinal = Math.max(currentWeightKg, estimatedAdultWeightFinal); // Ensure not less than current weight
}
// Let's cap it slightly above the reference weight to allow for variation.
estimatedAdultWeightFinal = Math.max(estimatedAdultWeightFinal, weightAt12WeeksRef * 1.1);
}
// Ensure estimated weight is not less than current weight
estimatedAdultWeightFinal = Math.max(estimatedAdultWeightFinal, currentWeightKg);
// Set the primary result
primaryResultElement.textContent = estimatedAdultWeightFinal.toFixed(1) + ' kg';
// — Intermediate Values —
var weightFactor = (currentWeightKg / currentAgeWeeks); // Simplified ratio
weightFactorElement.textContent = weightFactor.toFixed(2);
// Determine typical adult range based on breed group
var adultRangeText = "– kg";
if (breedGroup === 'small') adultRangeText = "1 – 10 kg";
else if (breedGroup === 'medium') adultRangeText = "10 – 25 kg";
else if (breedGroup === 'large') adultRangeText = "25 – 45 kg";
else if (breedGroup === 'giant') adultRangeText = "45+ kg";
adultRangeElement.textContent = adultRangeText;
// Update chart
updateChart(currentWeightKg, currentAgeWeeks, estimatedAdultWeightFinal, breedGroup);
}
var chart;
function initChart() {
var ctx = document.getElementById('growthChart').getContext('2d');
chart = new Chart(ctx, {
type: 'line',
data: {
labels: [], // Will be populated by updateChart
datasets: [{
label: 'Estimated Adult Weight',
data: [], // Will be populated by updateChart
borderColor: 'rgb(75, 192, 192)',
tension: 0.1,
fill: false
}, {
label: 'Reference Adult Weight',
data: [], // Will be populated by updateChart
borderColor: 'rgb(255, 99, 132)',
tension: 0.1,
fill: false,
borderDash: [5, 5]
}]
},
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
x: {
title: {
display: true,
text: 'Age (Weeks)'
}
},
y: {
title: {
display: true,
text: 'Weight (kg)'
}
}
}
}
});
}
function updateChart(currentWeight, currentAge, estimatedAdultWeight, breedGroup) {
if (!chart) initChart();
var labels = [];
var estimatedWeights = [];
var referenceWeights = [];
var referenceAdultWeight = parseFloat(document.getElementById('weightAt12Weeks').value) || breedData[breedGroup].referenceWeight;
var maxAge = Math.max(currentAge + 12, 52); // Project at least 12 weeks beyond current, or up to 52 weeks
if (maxAge > 78) maxAge = 78; // Cap projection for very old puppies
var growthFactor = (estimatedAdultWeight / currentWeight) / (maxAge / currentAge) ;
if (currentAge > 12) growthFactor = (estimatedAdultWeight / currentWeight) / ((maxAge – currentAge) / (maxAge – 12)) ; // adjust for older puppies
// Adjust growth factor based on breed group maturation
var maturationMultiplier = 1.0;
if (breedGroup === 'small') maturationMultiplier = 0.8; // Mature faster
else if (breedGroup === 'medium') maturationMultiplier = 1.0;
else if (breedGroup === 'large') maturationMultiplier = 1.2; // Mature slower
else if (breedGroup === 'giant') maturationMultiplier = 1.4; // Mature slowest
// Re-calculate growth factor more appropriately
// Estimate based on current age and projected adult weight
// Use simplified linear projection from current point to estimated adult weight.
// For plotting, we need points *leading up* to the estimated adult weight.
// A common curve is exponential or logistic, but linear interpolation is simpler for demonstration.
var currentWeightInput = parseFloat(document.getElementById('currentWeightKg').value);
var currentAgeInput = parseFloat(document.getElementById('currentAgeWeeks').value);
var refAdultWeightInput = parseFloat(document.getElementById('weightAt12Weeks').value) || breedData[breedGroup].referenceWeight;
// Simple linear projection from current point to estimated adult weight
var projectionPoints = 20; // Number of points to plot
var ageStep = (maxAge – currentAgeInput) / projectionPoints;
for (var i = 0; i maxAge) age = maxAge; // Ensure we don't exceed max age
// Calculate estimated weight at this 'age' using the same logic as primary calculation
var projectedWeightAtAge;
var k = 48; // Base multiplier
if (breedGroup === 'small') k = 30;
else if (breedGroup === 'medium') k = 40;
else if (breedGroup === 'giant') k = 60;
// Re-apply logic similar to `calculateWeight` but for arbitrary age
if (age <= 12) {
projectedWeightAtAge = (currentWeightInput / currentAgeInput) * k;
projectedWeightAtAge *= (age / 12) * 0.8; // Adjust for younger age
} else if (age <= 24) {
var factorAt12Weeks = 0.25;
var factorAt24Weeks = 0.75;
var currentFactor = factorAt12Weeks + (factorAt24Weeks – factorAt12Weeks) * ((age – 12) / (24 – 12));
// Scale by reference adult weight input
projectedWeightAtAge = refAdultWeightInput * currentFactor;
} else {
projectedWeightAtAge = refAdultWeightInput * 0.95; // Approaching final weight
// Ensure it doesn't go below current weight estimate logic
}
// Ensure projected weight is not less than current weight
projectedWeightAtAge = Math.max(projectedWeightAtAge, currentWeightInput * (age / currentAgeInput) );
projectedWeightAtAge = Math.max(projectedWeightAtAge, 0.1); // Minimum weight
labels.push(age.toFixed(1));
estimatedWeights.push(projectedWeightAtAge);
referenceWeights.push(refAdultWeightInput); // Constant line for reference adult weight
}
// Ensure current point is included
if (!labels.includes(currentAgeInput.toFixed(1))) {
labels.unshift(currentAgeInput.toFixed(1));
estimatedWeights.unshift(currentWeightInput);
referenceWeights.unshift(refAdultWeightInput);
}
chart.data.labels = labels;
chart.data.datasets[0].data = estimatedWeights;
chart.data.datasets[1].data = referenceWeights; // Plot reference adult weight
chart.update();
}
function resetCalculator() {
document.getElementById('breedGroup').value = 'medium';
document.getElementById('currentWeightKg').value = '';
document.getElementById('currentAgeWeeks').value = '';
document.getElementById('weightAt12Weeks').value = '';
// Clear errors
var errorElements = document.querySelectorAll('.error-message');
for (var i = 0; i < errorElements.length; i++) {
errorElements[i].textContent = '';
errorElements[i].classList.remove('visible');
}
// Reset results display
document.getElementById('primaryResult').textContent = '– kg';
document.getElementById('weightFactor').textContent = '–';
document.getElementById('adultRange').textContent = '– kg';
document.getElementById('referenceAdultWeight').textContent = '– kg';
// Reset chart if it exists
if (chart) {
chart.destroy();
chart = null;
initChart(); // Reinitialize with empty state
} else {
initChart();
}
// Reset breed group specific inputs/labels
updateBreedOptions();
populateBreedTable();
}
function copyResults() {
var primaryResult = document.getElementById('primaryResult').textContent;
var weightFactor = document.getElementById('weightFactor').textContent;
var adultRange = document.getElementById('adultRange').textContent;
var referenceAdultWeight = document.getElementById('referenceAdultWeight').textContent;
var breedGroup = document.getElementById('breedGroup');
var selectedBreedGroupName = breedData[breedGroup.value] ? breedData[breedGroup.value].name : 'N/A';
var formulaUsed = "Estimated Adult Weight ≈ Current Weight * (Reference Adult Weight / Estimated Current Weight at this Age). Reference Adult Weight is typically the breed's expected full-grown weight. The calculator estimates the puppy's current weight relative to its adult size based on age and breed group.";
var textToCopy = "— Puppy Adult Weight Estimate —\n\n" +
"Breed Group: " + selectedBreedGroupName + "\n" +
"Estimated Adult Weight: " + primaryResult + "\n" +
"Estimated Weight Factor (Ratio): " + weightFactor + "\n" +
"Typical Adult Weight Range (Group): " + adultRange + "\n" +
"Reference Adult Weight Used: " + referenceAdultWeight + "\n\n" +
"Formula Basis: " + formulaUsed;
// Use the Clipboard API
navigator.clipboard.writeText(textToCopy).then(function() {
// Success feedback (optional)
var copyButton = document.querySelector('button.copy');
var originalText = copyButton.textContent;
copyButton.textContent = 'Copied!';
setTimeout(function() {
copyButton.textContent = originalText;
}, 2000);
}).catch(function(err) {
console.error('Failed to copy text: ', err);
// Fallback for older browsers or specific environments
alert('Failed to copy. Please copy manually:\n' + textToCopy);
});
}
// Initial setup on page load
document.addEventListener('DOMContentLoaded', function() {
updateBreedOptions();
populateBreedTable();
initChart();
// Trigger initial calculation if defaults were set or if values exist on load
calculateWeight();
});