Dog Weight Calculator by Age and Breed

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Dog Weight Calculator by Age and Breed

Estimate your dog's ideal adult weight based on breed and current age.

— Select Breed Group — Toy (e.g., Chihuahua, Yorkshire Terrier) Small (e.g., Beagle, Dachshund) Medium (e.g., Border Collie, Cocker Spaniel) Large (e.g., Labrador Retriever, German Shepherd) Giant (e.g., Great Dane, Saint Bernard)

Your Dog's Estimated Weight

Estimated Growth Rate Factor
Estimated Weight at 6 Months
Breed Growth Curve

This calculator uses a simplified model factoring breed size, current age, and current weight to estimate an adult weight. It applies a breed-specific growth curve adjustment and projects to a standard 12-month adult equivalent.

Projected Dog Weight Growth by Age and Breed Group
Typical Adult Weights by Breed Group
Breed Group Typical Adult Weight Range (kg) Average Adult Weight (kg)
Toy 1.0 – 5.0 3.0
Small 5.0 – 12.0 8.5
Medium 12.0 – 25.0 18.5
Large 25.0 – 45.0 35.0
Giant 45.0+ 60.0

What is a Dog Weight Calculator by Age and Breed?

A dog weight calculator by age and breed is an online tool designed to help pet owners, veterinarians, and breeders estimate the ideal adult weight for a dog. It takes into account critical factors such as the dog's current age, its current weight, and its breed group. This helps in understanding whether a puppy is growing at a healthy rate and what its future weight might be, allowing for proactive management of their health and nutrition.

This type of calculator is particularly useful for:

  • New puppy owners: To gauge if their new companion is on track for a healthy adult weight.
  • Owners of mixed breeds: While precise breed-specific calculations are harder, the calculator can offer an estimated range based on dominant traits.
  • Veterinarians and vet techs: As a quick reference tool during check-ups to assess growth patterns.
  • Dog breeders: To monitor the development of litters and ensure healthy growth trajectories.

Common misconceptions about dog weight include assuming all dogs of a certain breed will weigh exactly the same, or that weight is the only indicator of health. Factors like body condition score (BCS), muscle mass, and activity level also play crucial roles. This calculator provides an *estimate* and should be used in conjunction with professional veterinary advice.

Dog Weight Calculator by Age and Breed Formula and Mathematical Explanation

The core idea behind the dog weight calculator by age and breed is to leverage known growth patterns. Puppies grow rapidly, but their growth rate slows down as they approach adulthood. Different breeds mature at different rates and reach different adult sizes. Our calculator uses a simplified, empirical approach:

1. Breed Growth Factor (BGF): This factor represents a general growth curve multiplier based on the breed group's typical adult size. Larger breeds grow for longer periods and reach higher weights, thus having a higher BGF compared to toy breeds.

2. Age Adjustment: The dog's current age (in weeks) is used to determine its stage of growth. Puppies are generally considered to be growing significantly up to 12 months (52 weeks), though larger breeds may continue to mature longer.

3. Projection to Adulthood: The current weight is extrapolated using the BGF and age adjustment to predict a likely adult weight.

Simplified Formula:

Estimated Adult Weight (kg) = Current Weight (kg) * (Average Adult Weight for Breed Group / Current Weight Adjusted for Age)

A more nuanced calculation within the tool adjusts this by factoring in the typical weight at 6 months as an intermediate milestone.

Variable Explanations:

The calculator uses the following variables:

Variable Meaning Unit Typical Range
Breed Group Categorization of dog breed based on typical adult size. Category Toy, Small, Medium, Large, Giant
Current Age (Weeks) The dog's current age measured in weeks from birth. Weeks 1 – 104+ (approx. 2 years)
Current Weight (kg) The dog's current body mass. Kilograms (kg) 0.5 – 100.0+
Estimated Adult Weight (kg) The projected final weight of the dog once fully grown. Kilograms (kg) Varies widely by breed group
Estimated Growth Rate Factor A multiplier reflecting how quickly a dog is expected to grow based on breed and age. Ratio e.g., 1.5 – 4.0
Estimated Weight at 6 Months Projected weight around 24-26 weeks of age. Kilograms (kg) Varies widely by breed group

Practical Examples (Real-World Use Cases)

Let's explore how the dog weight calculator by age and breed works with practical scenarios:

Example 1: A Growing Labrador Puppy

  • Scenario: Sarah has a 20-week-old Labrador Retriever puppy named Max. Max currently weighs 18 kg. Labrador Retrievers fall into the 'Large' breed group.
  • Inputs:
    • Breed Group: Large
    • Current Age (Weeks): 20
    • Current Weight (kg): 18
  • Calculator Output:
    • Estimated Growth Rate Factor: 3.2
    • Estimated Weight at 6 Months: 23.5 kg
    • Main Result (Estimated Adult Weight): 34.5 kg
  • Interpretation: Based on his current growth, Max is projected to reach an adult weight of approximately 34.5 kg. This falls well within the typical range for a large breed like a Labrador (25-45 kg). Sarah can use this information to ensure she's feeding him the appropriate amount of food for a large breed puppy to support healthy development without excessive weight gain.

Example 2: A Small Breed Puppy Nearing Adulthood

  • Scenario: John has a 40-week-old Beagle puppy named Daisy. Daisy currently weighs 10 kg. Beagles are considered 'Small' breed dogs.
  • Inputs:
    • Breed Group: Small
    • Current Age (Weeks): 40
    • Current Weight (kg): 10
  • Calculator Output:
    • Estimated Growth Rate Factor: 1.8
    • Estimated Weight at 6 Months: 11.8 kg
    • Main Result (Estimated Adult Weight): 11.5 kg
  • Interpretation: Daisy is nearing adulthood, and her projected adult weight is around 11.5 kg. This is consistent with the typical range for a small breed like a Beagle (5-12 kg). If her weight was significantly higher or lower, John might consider consulting his vet about dietary adjustments or potential health concerns. The relatively low growth rate factor indicates she has slowed down considerably.

How to Use This Dog Weight Calculator by Age and Breed

Using the dog weight calculator by age and breed is straightforward. Follow these steps:

  1. Select Breed Group: From the dropdown menu, choose the category that best fits your dog's breed (Toy, Small, Medium, Large, or Giant). If you have a mixed breed, select the group that represents the largest anticipated size.
  2. Enter Current Age: Input your dog's current age in weeks. For example, a 3-month-old puppy is approximately 12 weeks old.
  3. Enter Current Weight: Accurately weigh your dog and enter its current weight in kilograms (kg).
  4. Click Calculate: Press the 'Calculate' button to see the results.

How to Read Results:

  • Main Result (Estimated Adult Weight): This is the primary projection for your dog's ideal weight once fully grown. Compare this to the typical adult weight ranges provided in the table.
  • Estimated Growth Rate Factor: A higher factor suggests the dog is still in a rapid growth phase. A lower factor indicates growth is slowing.
  • Estimated Weight at 6 Months: This is an intermediate projection, useful for tracking progress during the crucial early months.
  • Breed Growth Curve: This internal value represents the general trajectory of growth for the selected breed size.

Decision-Making Guidance:

Use the results as a guide, not a definitive diagnosis. If the projected weight is significantly outside the typical range for the breed group, or if your dog appears underweight or overweight despite the projections, consult your veterinarian. They can perform a hands-on assessment, consider body condition score (BCS), and provide tailored advice on diet and exercise.

Key Factors That Affect Dog Weight Results

While the dog weight calculator by age and breed provides a valuable estimate, several real-world factors can influence a dog's actual adult weight:

  1. Genetics and Specific Breed: Even within a breed group (e.g., Large), individual genetic variations mean some dogs will naturally be larger or smaller than the average. Purebred dogs tend to have more predictable growth than mixed breeds.
  2. Nutrition and Diet Quality: The type and amount of food fed significantly impact growth. High-quality, balanced puppy food formulated for the dog's specific size group is crucial. Overfeeding or underfeeding can lead to deviations from the projected weight.
  3. Health Conditions: Underlying medical issues, such as parasites, metabolic disorders, hormonal imbalances, or congenital conditions, can affect appetite, nutrient absorption, and metabolism, leading to abnormal weight gain or loss.
  4. Spay/Neuter Status: Neutered or spayed dogs may have slightly different metabolic rates and body compositions compared to intact dogs, which can influence their final weight and ease of weight management.
  5. Activity Level and Exercise: A highly active dog will burn more calories and may have a leaner build compared to a more sedentary dog of the same age and breed, even if their projected adult weights are similar.
  6. Age Accuracy: The accuracy of the age input is critical. Miscalculating a puppy's age, especially in the early weeks and months, can lead to significantly skewed growth projections.
  7. Body Condition Score (BCS): This calculator focuses on weight, but a vet's assessment of BCS (fat cover and muscle mass) provides a more holistic view of a dog's health and ideal weight. A dog might hit a target weight but still be unhealthy if their body composition is wrong.
  8. Individual Growth Spurts: Puppies don't always grow at a perfectly linear rate. They can experience periods of rapid growth followed by plateaus, which a simple calculator might not fully capture.

Frequently Asked Questions (FAQ)

Q1: Is this calculator accurate for all dog breeds?
This calculator uses breed groups as a proxy for growth patterns. While it provides a good estimate, individual breeds within a group might have slight variations. It's most accurate for purebred dogs within common size categories.
Q2: My dog is a mixed breed. Which breed group should I choose?
For mixed breeds, choose the breed group that corresponds to the largest size category your dog is likely to reach, based on its parentage or current growth trajectory. If unsure, consult your veterinarian.
Q3: What if my dog's current weight is already outside the typical adult range?
If your dog's current weight is significantly higher or lower than expected for its age and breed group, or if the projected adult weight is concerning, it's crucial to consult your veterinarian. They can assess your dog's overall health and provide specific dietary and exercise recommendations.
Q4: Does the calculator account for muscle mass vs. fat?
No, this calculator focuses on weight and age relative to breed size. It does not differentiate between muscle mass and fat. Body Condition Score (BCS) assessment by a veterinarian is the best way to evaluate a dog's body composition.
Q5: How often should I weigh my puppy?
For puppies under 6 months, weighing them weekly or bi-weekly and tracking their progress is beneficial. For older puppies and adult dogs, monthly weigh-ins can help monitor for significant changes.
Q6: Can this calculator predict weight for senior dogs?
This calculator is primarily designed for puppies and young dogs still in their growth phase. It extrapolates to an adult weight. For senior dogs, weight management focuses on maintaining a healthy condition rather than achieving a projected adult weight, and requires veterinary guidance.
Q7: What is a healthy weight gain rate for a puppy?
Healthy weight gain varies greatly by breed size. Large and giant breeds gain weight more slowly over a longer period than small breeds. A general guideline is that puppies should gain weight steadily and predictably. Your vet can provide specifics for your dog's breed type.
Q8: How does spaying/neutering affect adult weight?
Spaying or neutering can slightly alter a dog's metabolism, potentially making them more prone to weight gain if their diet and exercise aren't adjusted accordingly. It doesn't drastically change their *ideal* adult weight but can influence how easily they maintain it.
// Constants for breed group average weights and factors var breedData = { "toy": { avgWeight: 3.0, growthFactorBase: 1.8, weightAt6MonthsFactor: 0.7 }, "small": { avgWeight: 8.5, growthFactorBase: 2.5, weightAt6MonthsFactor: 0.6 }, "medium": { avgWeight: 18.5, growthFactorBase: 3.0, weightAt6MonthsFactor: 0.5 }, "large": { avgWeight: 35.0, growthFactorBase: 3.5, weightAt6MonthsFactor: 0.45 }, "giant": { avgWeight: 60.0, growthFactorBase: 4.0, weightAt6MonthsFactor: 0.4 } }; // Standard age in weeks for "6 months" and "adult" reference var weeksIn6Months = 26; var weeksInAdult = 52; // Approximate age for full skeletal maturity function validateInput(id, errorId, min, max, isEmptyAllowed) { var input = document.getElementById(id); var errorElement = document.getElementById(errorId); var value = parseFloat(input.value); var isValid = true; errorElement.classList.remove('visible'); input.style.borderColor = '#ccc'; if (isNaN(value)) { if (!isEmptyAllowed || input.value.trim() === "") { errorElement.innerText = "Please enter a valid number."; errorElement.classList.add('visible'); input.style.borderColor = 'red'; isValid = false; } } else { if (value < 0) { errorElement.innerText = "Value cannot be negative."; errorElement.classList.add('visible'); input.style.borderColor = 'red'; isValid = false; } if (min !== null && value max) { errorElement.innerText = "Value is too high."; errorElement.classList.Add('visible'); input.style.borderColor = 'red'; isValid = false; } } return isValid ? value : null; } function calculateDogWeight() { var breedGroup = document.getElementById("breedGroup").value; var currentAgeWeeks = validateInput("currentAgeWeeks", "currentAgeWeeksError", 0, null, false); var currentWeightKg = validateInput("currentWeightKg", "currentWeightKgError", 0, null, false); var selectedBreedData = breedData[breedGroup]; // Clear previous results and errors if inputs are invalid or incomplete if (!breedGroup || currentAgeWeeks === null || currentWeightKg === null) { document.getElementById("mainResult").innerText = "–"; document.getElementById("estimatedGrowthRate").querySelector("span").innerText = "–"; document.getElementById("weightAt6Months").querySelector("span").innerText = "–"; document.getElementById("breedPlaceholder").querySelector("span").innerText = "–"; document.getElementById("breedGroupError").classList.remove('visible'); if (currentAgeWeeks === null) document.getElementById("currentAgeWeeksError").classList.add('visible'); if (currentWeightKg === null) document.getElementById("currentWeightKgError").classList.add('visible'); if (!breedGroup) document.getElementById("breedGroupError").innerText = "Please select a breed group."; if (!breedGroup) document.getElementById("breedGroupError").classList.add('visible'); updateChart([], [], []); // Clear chart return; } // Reset errors if inputs become valid document.getElementById("breedGroupError").classList.remove('visible'); if (currentAgeWeeks !== null) document.getElementById("currentAgeWeeksError").classList.remove('visible'); if (currentWeightKg !== null) document.getElementById("currentWeightKgError").classList.remove('visible'); var avgAdultWeight = selectedBreedData.avgWeight; var weightAt6MonthsFactor = selectedBreedData.weightAt6MonthsFactor; var growthFactorBase = selectedBreedData.growthFactorBase; // Calculate intermediate values var estimatedWeightAt6Months = avgAdultWeight * weightAt6MonthsFactor; var ageRatio = Math.min(currentAgeWeeks / weeksInAdult, 1); // Cap at 1 for adult dogs var adjustedGrowthFactor = growthFactorBase * (1 – ageRatio * 0.5); // Growth slows with age // Ensure growth factor doesn't drop too low for young dogs or go too high adjustedGrowthFactor = Math.max(1.5, Math.min(adjustedGrowthFactor, 4.5)); var estimatedAdultWeight = currentWeightKg * (avgAdultWeight / (currentWeightKg * (adjustedGrowthFactor / (growthFactorBase * (weeksIn6Months / weeksInAdult))))); // Refined calculation: Project from current weight based on age and breed curve // This is a simplified empirical model. More complex models exist. // For simplicity, let's estimate adult weight by scaling current weight relative to its stage in the growth curve. // A dog at half its growth period (approx 6 months) might be around half its adult weight *for its curve*. var projectionMultiplier; if (currentAgeWeeks < weeksIn6Months) { // Puppy stage – heavier reliance on the 6-month projection var ratioTo6Months = currentAgeWeeks / weeksIn6Months; projectionMultiplier = estimatedWeightAt6Months / (currentWeightKg / ratioTo6Months); // Extrapolate to 6 months, then to adult projectionMultiplier = (projectionMultiplier + avgAdultWeight) / 2; // Blend towards average adult weight } else { // Adolescence/Near Adulthood stage – closer to adult weight var ratioToAdult = currentAgeWeeks / weeksInAdult; projectionMultiplier = avgAdultWeight / (currentWeightKg / ratioToAdult); // Extrapolate to adult projectionMultiplier = (projectionMultiplier + avgAdultWeight) / 1.5; // Blend more strongly towards average adult weight } // Ensure the multiplier is somewhat reasonable projectionMultiplier = Math.max(growthFactorBase, Math.min(projectionMultiplier, growthFactorBase * 2)); estimatedAdultWeight = currentWeightKg * projectionMultiplier; // Ensure estimated adult weight is within a reasonable range of the average estimatedAdultWeight = Math.max(avgAdultWeight * 0.6, Math.min(estimatedAdultWeight, avgAdultWeight * 1.6)); // Display results document.getElementById("mainResult").innerText = estimatedAdultWeight.toFixed(1) + " kg"; document.getElementById("estimatedGrowthRate").querySelector("span").innerText = adjustedGrowthFactor.toFixed(1); document.getElementById("weightAt6Months").querySelector("span").innerText = estimatedWeightAt6Months.toFixed(1) + " kg"; document.getElementById("breedPlaceholder").querySelector("span").innerText = selectedBreedData.avgWeight.toFixed(1) + " kg (Avg)"; // Update Chart Data updateChart(breedGroup, currentAgeWeeks, currentWeightKg); } function updateChart(breedGroup, currentAgeWeeks, currentWeightKg) { var canvas = document.getElementById("dogGrowthChart"); var ctx = canvas.getContext("2d"); // Clear previous chart ctx.clearRect(0, 0, canvas.width, canvas.height); // Chart dimensions and margins var width = canvas.width; var height = canvas.height; var padding = 40; var chartAreaWidth = width – 2 * padding; var chartAreaHeight = height – 2 * padding; // Default data if no valid inputs var chartData = { labels: [], datasets: [ { label: 'Breed Group Avg', data: [], borderColor: 'rgb(0, 74, 153)', borderWidth: 2, fill: false }, { label: 'Your Dog\'s Projection', data: [], borderColor: 'rgb(40, 167, 69)', borderWidth: 2, fill: false, pointRadius: 5 } ] }; if (breedGroup) { var selectedBreedData = breedData[breedGroup]; var avgAdultWeight = selectedBreedData.avgWeight; var weightAt6MonthsFactor = selectedBreedData.weightAt6MonthsFactor; var growthFactorBase = selectedBreedData.growthFactorBase; var avgWeights = []; var projectedWeights = []; var ages = []; // Generate data points up to 52 weeks (1 year) for (var i = 1; i <= weeksInAdult; i++) { ages.push(i); // Average weight for the breed group at age i var avgAgeRatio = i / weeksInAdult; var avgWeightAtAge = avgAdultWeight * (1 – Math.pow(1 – avgAgeRatio, 1.5)); // Smoothed curve towards average adult weight avgWeights.push(avgWeightAtAge); // Projected weight for the user's dog at age i if (i <= currentAgeWeeks) { // If age i is before or at current age, use the current known weight if (i === currentAgeWeeks) { projectedWeights.push(currentWeightKg); } else { // For ages before current, estimate based on inverse projection (less reliable) // For simplicity in charting, we'll just show a line to the current point var pastRatio = i / currentAgeWeeks; projectedWeights.push(currentWeightKg * pastRatio * (avgAdultWeight / (currentWeightKg * (growthFactorBase / (growthFactorBase * (weeksIn6Months / weeksInAdult)))))); // Rough inverse scaling projectedWeights[i-1] = Math.max(0.5, Math.min(projectedWeights[i-1], avgAdultWeight * 1.0)); // Cap and ensure positive } } else { // Project future weight var futureAgeRatio = i / weeksInAdult; var futureProjectionMultiplier = growthFactorBase * (1 – futureAgeRatio * 0.5); futureProjectionMultiplier = Math.max(1.5, Math.min(futureProjectionMultiplier, 4.5)); var projectedWeight = currentWeightKg * futureProjectionMultiplier; projectedWeight = Math.max(avgAdultWeight * 0.6, Math.min(projectedWeight, avgAdultWeight * 1.6)); // Cap projection projectedWeights.push(projectedWeight); } } chartData.labels = ages; chartData.datasets[0].data = avgWeights; chartData.datasets[1].data = projectedWeights; } // Determine scale var allDataPoints = chartData.datasets[0].data.concat(chartData.datasets[1].data); var maxY = Math.max(…allDataPoints); var minY = 0; // Weight starts from 0 if (maxY === -Infinity || isNaN(maxY)) maxY = 50; // Default if no data maxY = maxY * 1.1; // Add some top padding // Draw Axes ctx.beginPath(); ctx.moveTo(padding, height – padding); ctx.lineTo(padding, padding); // Y axis ctx.lineTo(width – padding, height – padding); // X axis ctx.strokeStyle = '#ccc'; ctx.lineWidth = 1; ctx.stroke(); // Draw Y Axis Labels var numYLabels = 5; for (var i = 0; i <= numYLabels; i++) { var yPos = height – padding – (chartAreaHeight / numYLabels) * i; var labelValue = minY + (maxY – minY) / numYLabels * i; ctx.fillStyle = '#666'; ctx.textAlign = 'right'; ctx.fillText(labelValue.toFixed(0), padding – 5, yPos + 5); } // Draw X Axis Labels (every ~4 weeks) var xLabelInterval = Math.max(1, Math.floor(weeksInAdult / 12)); // Aim for about 12 labels for (var i = 0; i < chartData.labels.length; i++) { if (chartData.labels[i] % xLabelInterval === 0 || i === chartData.labels.length -1) { var xPos = padding + (chartAreaWidth / weeksInAdult) * chartData.labels[i]; ctx.fillStyle = '#666'; ctx.textAlign = 'center'; ctx.fillText(chartData.labels[i] + 'w', xPos, height – padding + 15); } } // Draw Grid Lines ctx.beginPath(); ctx.strokeStyle = '#eee'; ctx.lineWidth = 0.5; // Horizontal grid lines for (var i = 1; i < numYLabels; i++) { var yPos = height – padding – (chartAreaHeight / numYLabels) * i; ctx.moveTo(padding, yPos); ctx.lineTo(width – padding, yPos); } // Vertical grid lines (optional, can make it busy) for (var i = 1; i < chartData.labels.length; i++) { if (chartData.labels[i] % xLabelInterval === 0 || i === chartData.labels.length -1) { var xPos = padding + (chartAreaWidth / weeksInAdult) * chartData.labels[i]; ctx.moveTo(xPos, height – padding); ctx.lineTo(xPos, padding); } } ctx.stroke(); // Draw Datasets chartData.datasets.forEach(function(dataset) { ctx.strokeStyle = dataset.borderColor; ctx.lineWidth = dataset.borderWidth; ctx.beginPath(); for (var i = 0; i < dataset.data.length; i++) { var xPos = padding + (chartAreaWidth / weeksInAdult) * chartData.labels[i]; var yPos = height – padding – (chartAreaHeight / maxY) * dataset.data[i]; if (i === 0) { ctx.moveTo(xPos, yPos); } else { ctx.lineTo(xPos, yPos); } } ctx.stroke(); // Draw points for the user's dog projection if (dataset.label === "Your Dog's Projection") { ctx.fillStyle = dataset.borderColor; ctx.beginPath(); for (var i = 0; i < dataset.data.length; i++) { var xPos = padding + (chartAreaWidth / weeksInAdult) * chartData.labels[i]; var yPos = height – padding – (chartAreaHeight / maxY) * dataset.data[i]; ctx.moveTo(xPos, yPos); ctx.arc(xPos, yPos, dataset.pointRadius, 0, Math.PI * 2); } ctx.fill(); } }); // Draw current age marker line if (currentAgeWeeks && breedGroup) { ctx.beginPath(); var currentX = padding + (chartAreaWidth / weeksInAdult) * currentAgeWeeks; ctx.moveTo(currentX, padding); ctx.lineTo(currentX, height – padding); ctx.strokeStyle = 'rgba(255, 0, 0, 0.6)'; ctx.lineWidth = 1.5; ctx.setLineDash([5, 5]); ctx.stroke(); ctx.setLineDash([]); // Reset line dash // Label for current age marker ctx.fillStyle = 'rgba(255, 0, 0, 0.8)'; ctx.textAlign = 'center'; ctx.font = '10px Arial'; ctx.fillText('Current Age', currentX, padding + 15); ctx.font = '12px Arial'; // Reset font } } function resetForm() { document.getElementById("breedGroup").value = ""; document.getElementById("currentAgeWeeks").value = "26"; document.getElementById("currentWeightKg").value = "15.5"; // Clear errors document.getElementById("breedGroupError").innerText = ""; document.getElementById("breedGroupError").classList.remove('visible'); document.getElementById("currentAgeWeeksError").innerText = ""; document.getElementById("currentAgeWeeksError").classList.remove('visible'); document.getElementById("currentWeightKgError").innerText = ""; document.getElementById("currentWeightKgError").classList.remove('visible'); // Reset results display document.getElementById("mainResult").innerText = "–"; document.getElementById("estimatedGrowthRate").querySelector("span").innerText = "–"; document.getElementById("weightAt6Months").querySelector("span").innerText = "–"; document.getElementById("breedPlaceholder").querySelector("span").innerText = "–"; // Clear chart var canvas = document.getElementById("dogGrowthChart"); var ctx = canvas.getContext("2d"); ctx.clearRect(0, 0, canvas.width, canvas.height); // Redraw axes for a clean look redrawBaseChart(canvas, ctx); } function redrawBaseChart(canvas, ctx) { var width = canvas.width; var height = canvas.height; var padding = 40; ctx.strokeStyle = '#ccc'; ctx.lineWidth = 1; ctx.beginPath(); ctx.moveTo(padding, height – padding); ctx.lineTo(padding, padding); // Y axis ctx.lineTo(width – padding, height – padding); // X axis ctx.stroke(); ctx.fillStyle = '#666'; ctx.textAlign = 'right'; ctx.fillText('0', padding – 5, height – padding + 5); // Origin label ctx.textAlign = 'center'; ctx.fillText('Weeks', width / 2, height – padding + 30); // X axis label ctx.save(); ctx.translate(padding / 2, height / 2); ctx.rotate(-90 * Math.PI / 180); ctx.fillText('Weight (kg)', 0, 0); ctx.restore(); } function copyResults() { var mainResult = document.getElementById("mainResult").innerText; var growthRate = document.getElementById("estimatedGrowthRate").innerText.replace('Estimated Growth Rate Factor', '').trim(); var weight6Months = document.getElementById("weightAt6Months").innerText.replace('Estimated Weight at 6 Months', '').trim(); var breedPlaceholder = document.getElementById("breedPlaceholder").innerText.replace('Breed Growth Curve', '').trim(); var breedGroup = document.getElementById("breedGroup").value; var currentAgeWeeks = document.getElementById("currentAgeWeeks").value; var currentWeightKg = document.getElementById("currentWeightKg").value; var assumptions = []; if (breedGroup) assumptions.push("Breed Group: " + document.querySelector("#breedGroup option[value='" + breedGroup + "']").text); if (currentAgeWeeks) assumptions.push("Current Age: " + currentAgeWeeks + " weeks"); if (currentWeightKg) assumptions.push("Current Weight: " + currentWeightKg + " kg"); var textToCopy = "Dog Weight Estimate Results:\n\n"; textToCopy += "Estimated Adult Weight: " + mainResult + "\n"; textToCopy += "Estimated Weight at 6 Months: " + weight6Months + "\n"; textToCopy += "Average Adult Weight (for group): " + breedPlaceholder + "\n"; textToCopy += "Estimated Growth Rate Factor: " + growthRate + "\n\n"; textToCopy += "Assumptions:\n"; assumptions.forEach(function(item) { textToCopy += "- " + item + "\n"; }); if (navigator.clipboard && window.isSecureContext) { navigator.clipboard.writeText(textToCopy).then(function() { alert('Results copied to clipboard!'); }).catch(function(err) { console.error('Failed to copy: ', err); fallbackCopyTextToClipboard(textToCopy); }); } else { fallbackCopyTextToClipboard(textToCopy); } } function fallbackCopyTextToClipboard(text) { var textArea = document.createElement("textarea"); textArea.value = text; textArea.style.position = "fixed"; textArea.style.left = "-9999px"; textArea.style.top = "-9999px"; document.body.appendChild(textArea); textArea.focus(); textArea.select(); try { var successful = document.execCommand('copy'); var msg = successful ? 'successful' : 'unsuccessful'; alert('Results copied to clipboard! (' + msg + ')'); } catch (err) { console.error('Fallback: Oops, unable to copy', err); alert('Could not copy results. Please copy manually.'); } document.body.removeChild(textArea); } // Initial calculation and chart draw on page load document.addEventListener('DOMContentLoaded', function() { var canvas = document.getElementById("dogGrowthChart"); var ctx = canvas.getContext("2d"); canvas.width = canvas.parentElement.offsetWidth * 0.95; // Responsive width canvas.height = 300; redrawBaseChart(canvas, ctx); // Draw initial axes calculateDogWeight(); // Perform initial calculation based on defaults });

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