Determine your scientifically recommended ideal body weight range. This professional weight calculator with age and height utilizes the Devine, Robinson, and Miller formulas to provide accurate health assessments.
Metric (cm / kg)
Imperial (ft+in / lbs)
Select your preferred measurement system.
Male
Female
Biological sex affects body composition formulas.
Please enter a valid age (15-100).
Used to adjust BMR and health recommendations.
Please enter a valid height (100cm – 250cm).
Feet and Inches
Optional: Enter to calculate your current BMI.
Estimated Ideal Weight Range
66.5 – 73.5 kg
Based on the Devine Formula adjusted for healthy BMI buffer.
22.9
Current BMI
Healthy
Weight Status
1,650
Daily BMR (Calories)
Weight Status Analysis
Figure 1: Visual comparison of your current weight vs. healthy BMI zones.
Detailed Formula Breakdown
Method/Formula
Ideal Weight Estimate
Formula Focus
Table 1: Comparison of different medical standards for ideal body weight.
What is a Weight Calculator with Age and Height?
A weight calculator with age and height is a digital health tool designed to estimate the ideal body weight (IBW) for an individual based on anthropometric data. Unlike a simple scale that only tells you your total mass, this calculator contextualizes that number using established medical formulas—primarily the Devine, Miller, and Robinson equations—along with the Body Mass Index (BMI) standard.
While "ideal weight" is a subjective term, in a medical context, it refers to a weight range associated with the lowest mortality rates for a given height and gender. This tool is essential for anyone looking to set realistic fitness goals, monitor health progress, or understand how their body composition compares to population averages.
Common Misconceptions: Many people believe there is a single "perfect" number for their weight. In reality, a healthy weight is a range. Factors like muscle mass, bone density (frame size), and age play significant roles. For instance, a weight calculator with age and height often adjusts recommendations for older adults, as slightly higher weight reserves can be protective in geriatric health.
Weight Calculator Formula and Mathematical Explanation
To determine your ideal weight, this calculator primarily employs the Devine Formula (1974), which is the most widely used equation in medical settings for dosing medications and assessing health. It essentially calculates a baseline weight for a height of 5 feet and adds a set amount for every inch above that.
The Devine Formula
The calculation differs slightly by gender due to physiological differences in body composition:
Men: IBW = 50 kg + 2.3 kg × (Height in inches – 60)
Women: IBW = 45.5 kg + 2.3 kg × (Height in inches – 60)
Variables Definition
Variable
Meaning
Unit
Typical Range
IBW
Ideal Body Weight
kg / lbs
45 – 100+ kg
Height
Vertical stature
inches
58 – 84 in
Base Weight
Starting constant
kg
50 (M) / 45.5 (F)
BMI
Body Mass Index
kg/m²
18.5 – 24.9 (Healthy)
Table 2: Key variables used in weight calculation algorithms.
Practical Examples (Real-World Use Cases)
Example 1: The Fitness Enthusiast
Profile: Mark is a 35-year-old male, 180 cm (approx 5ft 11in) tall. He wants to know his medical ideal weight baseline using the weight calculator with age and height.
Result: Mark's strict medical ideal weight is approximately 75.3 kg (166 lbs). However, a healthy range would extend roughly 10% above and below this figure depending on his muscle mass.
Example 2: Health Monitoring for Seniors
Profile: Susan is a 65-year-old female, 160 cm (approx 5ft 3in) tall.
Result: The formula suggests roughly 52.4 kg (115 lbs).
Interpretation: Since Susan is 65, strict adherence to the lower end of the BMI scale might not be ideal. A physician might recommend she maintain a weight slightly above this calculated ideal to ensure resilience against illness, showing why interpreting the weight calculator with age and height results requires context.
How to Use This Weight Calculator with Age and Height
Select Unit System: Choose between Metric (cm/kg) or Imperial (ft/lbs) using the dropdown menu at the top.
Enter Biological Details: Input your gender and age. These factors subtly influence the Basal Metabolic Rate (BMR) and recommended ranges.
Input Height: Be as precise as possible. If you don't know your exact height, measure yourself against a wall without shoes.
Enter Current Weight (Optional): Providing your current weight allows the tool to calculate your current BMI and visualize where you stand relative to the ideal zone.
Review Results:
The Green Box shows your calculated ideal weight range.
The Chart visualizes your position: Underweight, Healthy, Overweight, or Obese.
The Table compares results from different medical formulas (Devine vs. Robinson).
Key Factors That Affect Weight Calculator Results
When using a weight calculator with age and height, it is crucial to understand that the output is a statistical average, not a biological mandate. Several factors influence your specific healthy weight:
1. Muscle Mass vs. Fat Mass
Muscle tissue is denser than fat tissue. An athlete may register as "Overweight" on a standard BMI or weight calculator because of heavy muscle mass, despite having low body fat and excellent metabolic health.
2. Bone Frame Size
Formulas like Devine do not account for frame size. Individuals with a larger skeletal frame (broad shoulders, thick wrists) naturally carry more weight. "Small frame" individuals should aim for the lower end of the calculator's range, while "large frame" individuals should aim for the higher end.
3. Age and Metabolism
As we age, our metabolism slows, and we naturally lose muscle mass (sarcopenia). A weight calculator with age and height is useful here because it reminds us that while weight might remain stable, body composition often changes. Older adults often require a slightly higher BMI to protect against osteoporosis and frailty.
4. Gender Differences
Men typically carry more muscle mass and heavier bones than women, leading to higher ideal weight calculations for the same height. Women generally have a higher essential body fat percentage necessary for hormonal health.
5. Hydration Levels
Your weight can fluctuate by 1-2 kg (2-4 lbs) daily based on water retention, salt intake, and hydration. Never treat a single weigh-in as definitive; look for trends over time.
6. Distribution of Fat
Visceral fat (fat stored around organs) is more dangerous than subcutaneous fat (under the skin). Two people can have the same weight and height, but if one carries weight primarily in the abdomen, they are at higher risk for metabolic disease regardless of what the calculator says.
Frequently Asked Questions (FAQ)
How accurate is this weight calculator with age and height?
It is highly accurate for the general population as it uses validated medical formulas. However, it does not measure body fat percentage. Athletes or pregnant women should consult a doctor for personalized assessments.
Why does age matter in weight calculation?
Age affects metabolic rate and recommended BMI ranges. While the core calculation relies heavily on height, interpreting the result changes with age; slightly higher weights are often acceptable and protective for seniors.
What is the difference between BMI and IBW?
BMI (Body Mass Index) is a broad screening tool categorized by ranges (e.g., 18.5-24.9). IBW (Ideal Body Weight) attempts to pinpoint a specific target weight based on height. Both should be used as guidelines, not strict rules.
Should I diet if I am above the calculated weight?
Not necessarily. If you are muscular or have a large frame, being "above" the average may be healthy. Focus on body composition and blood markers (like cholesterol and blood pressure) rather than just the number on the scale.
Does this calculator apply to children?
No. Children and teenagers require specialized growth charts (percentiles) because they are still developing. This tool is designed for adults over 18.
Can I change the units from metric to imperial?
Yes, use the "Unit System" dropdown at the top of the calculator to switch between Kilograms/Centimeters and Pounds/Feet+Inches.
What is the Robinson Formula?
The Robinson formula (1983) is another method for calculating ideal weight. It often yields slightly lower values than the Devine formula and is included in the breakdown table for comparison.
How often should I check my weight?
Checking once a week at the same time of day (usually morning) is recommended to track trends without obsessing over daily fluctuations.
Related Tools and Internal Resources
Explore our other health and financial planning tools to manage your overall well-being:
BMI Calculator Pro
A dedicated tool focusing strictly on Body Mass Index categories and health risks.
Calorie Deficit Planner
Calculate exactly how many calories you need to burn to reach your ideal weight derived from the weight calculator with age and height.
Body Fat Percentage Estimator
Go beyond simple weight and estimate your lean mass vs. fat mass using tape measurements.
Macro Nutrient Splitter
Determine the right balance of protein, carbs, and fats for your specific age and activity level.
Health Insurance Cost Estimator
Understand how maintaining a healthy weight can positively impact your long-term insurance premiums and financial health.
// — VARIABLES & CONFIG —
// Using var as requested
var unitSystem = 'metric';
// — UTILITY FUNCTIONS —
function getEl(id) {
return document.getElementById(id);
}
function toggleUnits() {
var system = getEl('unitSystem').value;
unitSystem = system;
var metricGroup = getEl('metricHeightGroup');
var imperialGroup = getEl('imperialHeightGroup');
var weightLabel = getEl('weightUnitLabel');
var weightInput = getEl('currentWeight');
if (system === 'metric') {
metricGroup.style.display = 'block';
imperialGroup.style.display = 'none';
weightLabel.textContent = '(kg)';
// Convert current lbs to kg for smooth UX
if(weightInput.value) {
weightInput.value = Math.round(weightInput.value * 0.453592);
}
} else {
metricGroup.style.display = 'none';
imperialGroup.style.display = 'block';
weightLabel.textContent = '(lbs)';
// Convert current kg to lbs for smooth UX
if(weightInput.value) {
weightInput.value = Math.round(weightInput.value * 2.20462);
}
}
calculateWeight();
}
function getInputs() {
var gender = getEl('gender').value;
var age = parseFloat(getEl('age').value);
var weightVal = parseFloat(getEl('currentWeight').value);
var heightCm = 0;
if (unitSystem === 'metric') {
heightCm = parseFloat(getEl('heightCm').value);
} else {
var ft = parseFloat(getEl('heightFt').value) || 0;
var in_ = parseFloat(getEl('heightIn').value) || 0;
heightCm = ((ft * 12) + in_) * 2.54;
// Convert input weight (lbs) to kg for internal calc
weightVal = weightVal * 0.453592;
}
return {
gender: gender,
age: age,
weightKg: weightVal,
heightCm: heightCm
};
}
// — CALCULATION LOGIC —
function calculateWeight() {
var inputs = getInputs();
// Validation
var ageValid = inputs.age >= 15 && inputs.age = 100 && inputs.heightCm <= 250;
getEl('ageError').style.display = ageValid ? 'none' : 'block';
getEl('heightError').style.display = heightValid ? 'none' : 'block';
if (!ageValid || !heightValid) return;
var heightInches = inputs.heightCm / 2.54;
var heightOver60 = heightInches – 60;
if (heightOver60 < 0) heightOver60 = 0;
// 1. Devine Formula (Primary)
var devineBase = (inputs.gender === 'male') ? 50 : 45.5;
var devineWeight = devineBase + (2.3 * heightOver60);
// 2. Robinson Formula
var robinsonBase = (inputs.gender === 'male') ? 52 : 49;
var robinsonRate = (inputs.gender === 'male') ? 1.9 : 1.7;
var robinsonWeight = robinsonBase + (robinsonRate * heightOver60);
// 3. BMI Calculation
var heightM = inputs.heightCm / 100;
var bmi = inputs.weightKg / (heightM * heightM);
// 4. Healthy BMI Range Weights (18.5 – 24.9)
var minHealthyWeight = 18.5 * (heightM * heightM);
var maxHealthyWeight = 24.9 * (heightM * heightM);
// 5. BMR (Mifflin-St Jeor)
// Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
// Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
var bmr = (10 * inputs.weightKg) + (6.25 * inputs.heightCm) – (5 * inputs.age);
if (inputs.gender === 'male') {
bmr += 5;
} else {
bmr -= 161;
}
// — UPDATE UI —
// Format for display
var displayUnit = (unitSystem === 'metric') ? 'kg' : 'lbs';
var convert = (unitSystem === 'metric') ? 1 : 2.20462;
var idealLow = minHealthyWeight * convert;
var idealHigh = maxHealthyWeight * convert;
var devineDisp = devineWeight * convert;
var robinsonDisp = robinsonWeight * convert;
// Main Result: Range based on BMI + Devine Center
getEl('idealWeightResult').innerHTML =
Math.round(idealLow) + ' – ' + Math.round(idealHigh) + ' ' + displayUnit;
getEl('bmiResult').innerHTML = bmi.toFixed(1);
getEl('bmrResult').innerHTML = Math.round(bmr).toLocaleString();
// Status
var status = '';
var color = '';
if (bmi < 18.5) { status = 'Underweight'; color = '#ffc107'; }
else if (bmi < 25) { status = 'Healthy Weight'; color = '#28a745'; }
else if (bmi < 30) { status = 'Overweight'; color = '#fd7e14'; }
else { status = 'Obese'; color = '#dc3545'; }
var statusEl = getEl('statusResult');
statusEl.innerHTML = status;
statusEl.style.color = color;
// Breakdown Table
var tableHtml = '';
tableHtml += '