Ideal Weight Calculator – Calculate Your Ideal Body Weight
Ideal Weight Calculator
This calculator estimates a reference body weight from your height and sex using an established formula. Pick a formula, or compare all four — the result is a formula-based estimate, not a universally correct or medically prescribed weight.
Last updated: August 2026 · Written by the CalculatorSearch team · Medically reviewed by [Add a genuine credentialed reviewer before publishing — do not leave as placeholder]
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Ideal body weight formulas are simple height-based estimates originally developed for clinical use (such as medication dosing). Different formulas give different numbers, and none accounts for muscle, body composition, or individual health. This tool is for adults — for ages 2–19 use a child BMI calculator.
What is an ideal weight calculator?
An ideal weight calculator estimates a reference body weight from your height using a selected formula. Common formulas include Devine, Robinson, Miller, and Hamwi. They can produce different results and should be treated as estimates — not a universally correct or medically prescribed weight.
Key Facts
Ideal weight is a formula-based reference estimate.
Primary input: height (with sex).
Common formulas: Devine, Robinson, Miller, Hamwi.
Different formulas can give different results.
BMI is a separate height-and-weight calculation.
Healthy weight is a range, not the same as ideal weight.
Adult formulas don't apply to children.
It's not a personalised medical target.
The Formulas
Each formula starts from a base weight at 5 feet (60 inches) and adds a set amount per inch above that. Below 5 feet, this calculator uses the base weight only, since the equations weren't designed to extrapolate downward.
Devine — Men: 50 kg + 2.3 kg/in over 5 ft · Women: 45.5 kg + 2.3 kg/in
Robinson — Men: 52 kg + 1.9 kg/in · Women: 49 kg + 1.7 kg/in
Miller — Men: 56.2 kg + 1.41 kg/in · Women: 53.1 kg + 1.36 kg/in
Hamwi — Men: 106 lb + 6 lb/in · Women: 100 lb + 5 lb/in (then converted to kg)
Formula
Origin
Men (base + per inch)
Women (base + per inch)
Devine
1974, drug dosing
50 kg + 2.3 kg
45.5 kg + 2.3 kg
Robinson
1983
52 kg + 1.9 kg
49 kg + 1.7 kg
Miller
1983
56.2 kg + 1.41 kg
53.1 kg + 1.36 kg
Hamwi
1964
106 lb + 6 lb
100 lb + 5 lb
These formulas were developed from different datasets for different purposes, so they aren't interchangeable — which is exactly why "ideal weight" varies between websites.
Worked Examples
5'4" woman (64 in)
4 in over 5 ft Devine 45.5 + 2.3×4 = 54.7 kg (121 lb) Robinson 49 + 1.7×4 = 55.8 kg · Miller 53.1 + 1.36×4 = 58.5 kg · Hamwi (100 + 5×4)/2.2046 = 54.4 kg
5'10" man (70 in)
10 in over 5 ft Devine 50 + 2.3×10 = 73.0 kg (161 lb) Robinson 71.0 kg · Miller 70.3 kg · Hamwi 75.3 kg
175 cm man (metric)
175 cm = 68.9 in → 8.9 in over 5 ft Devine ≈ 70.5 kg · Robinson ≈ 68.9 kg · Miller ≈ 68.7 kg · Hamwi ≈ 72.3 kg
Same height, four formulas (5'10" man)
Devine 73.0 · Robinson 71.0 · Miller 70.3 · Hamwi 75.3 kg — a ~5 kg spread from formula choice alone.
How Ideal Weight Compares to Other Measures
This page owns one job: a formula-based reference weight. Related tools answer different questions, so they complement rather than duplicate it.
Ideal weight vs BMI
BMI is a ratio you calculate from weight and height; ideal weight is estimated from height and sex without your current weight. Compute BMI with the BMI calculator.
Ideal weight vs healthy weight
This is the key distinction: ideal weight is a single formula-based number; a healthy weight is a BMI-based range for your height. Don't use the terms interchangeably.
Ideal weight vs body fat percentage
Two people at the same ideal weight can have very different composition. Body fat percentage estimates the fat share of your weight — see the body fat calculator.
Ideal weight vs lean body mass
Ideal weight is a total-weight reference; lean body mass estimates your non-fat mass. They measure different things — see the lean body mass calculator.
Ideal weight for children and teens
Adult IBW formulas must not be applied to anyone aged 2–19; children are assessed with BMI-for-age percentiles. Use the child BMI calculator. This tool is for adults.
Ideal weight vs body surface area
Body surface area is a separate body-size measure for specific clinical uses, not a weight reference. See the body surface area calculator.
Ideal weight vs adjusted body weight
Adjusted body weight modifies IBW using a further formula for particular clinical/nutrition contexts — a different calculation, and not drug-dosing advice here. See the adjusted body weight calculator.
Ideal weight vs body shape
Body shape describes proportions and fat distribution; it doesn't set an ideal weight. Explore the body shape calculator.
Why Ideal Weight Formulas May Not Fit Everyone
Height-based IBW equations can't account for muscle mass, body fat, bone structure, body proportions, athletic build, age-related composition changes, health conditions, or pregnancy. A very muscular person may weigh well above every formula's estimate while carrying low body fat. Athletes needn't ignore weight entirely, but should read these numbers alongside composition measures like the body fat, lean body mass, or FFMI calculators.
Sex, age, and pregnancy
The formulas use sex-specific coefficients, which is why sex changes the result. They don't use age at all, so entering an age won't change the estimate. And they aren't designed for pregnancy, which is assessed with pregnancy-specific clinical guidance — don't treat an IBW number as a pregnancy target.
Ideal weight is not a healthy-weight range. If you want the weight range that matches the healthy BMI band for your height, use the healthy weight calculator — that answers a different question from this page.
Frequently Asked Questions
What is an ideal weight?
In this calculator, ideal weight is a reference body weight estimated from your height and sex using an established formula. It's a formula-based estimate, not a universally correct or medically prescribed weight.
How is ideal weight calculated?
Traditional formulas start from a base weight at 5 feet of height and add a fixed amount for each inch above 5 feet, with different coefficients for men and women. This tool implements Devine, Robinson, Miller, and Hamwi.
What is the ideal weight for my height?
Enter your height and sex above to see estimates. For a 5'10" man, the formulas give roughly 70–75 kg (155–166 lb) depending on which one you use.
What is ideal body weight?
Ideal body weight (IBW) is a reference value from height-based formulas originally developed for clinical purposes such as medication dosing. It's an estimate, not a personalised health target.
What is the Devine ideal weight formula?
Devine: men = 50 kg + 2.3 kg per inch over 5 feet; women = 45.5 kg + 2.3 kg per inch over 5 feet. It's the most widely used IBW formula.
What is the Robinson ideal weight formula?
Robinson (1983): men = 52 kg + 1.9 kg per inch over 5 feet; women = 49 kg + 1.7 kg per inch over 5 feet.
What is the Miller ideal weight formula?
Miller (1983): men = 56.2 kg + 1.41 kg per inch over 5 feet; women = 53.1 kg + 1.36 kg per inch over 5 feet.
What is the Hamwi ideal weight formula?
Hamwi (1964): men = 106 lb + 6 lb per inch over 5 feet; women = 100 lb + 5 lb per inch over 5 feet, then converted to kg.
Why do ideal weight calculators give different results?
Each formula was developed from different data and for different purposes, so their base weights and per-inch increments differ. That's why the same height can yield several different "ideal" weights.
Is ideal weight the same as healthy weight?
No. Ideal weight is a single formula-based reference number; a healthy weight is a BMI-based range for your height. They're different concepts and shouldn't be used interchangeably.
Is ideal weight the same as BMI?
No. BMI is a ratio of weight to height that you calculate from both. Ideal weight is estimated from height and sex using a formula, without needing your current weight.
Does BMI determine ideal weight?
No. BMI and IBW formulas are separate methods. A BMI-based healthy weight range and a formula-based ideal weight can give different numbers for the same person.
Does age affect ideal weight?
The traditional IBW formulas don't use age — they depend only on height and sex. Entering an age doesn't change the result.
Does sex affect ideal weight?
Yes. The historical formulas use different base weights and increments for men and women, so sex changes the estimate.
Can muscular people use an ideal weight calculator?
They can, but height-based formulas don't account for muscle mass, so a very muscular person may weigh well above the estimate while being lean. Body fat or lean mass tools add context.
Is ideal weight accurate?
It's a rough reference, not a precise or individualised figure. The formulas are simple height-based estimates and don't reflect body composition or individual health.
Is ideal weight medically recommended?
IBW formulas are used in some clinical settings, mainly for calculations like medication dosing, but a formula result is not a personal weight goal. Talk with a professional about what's right for you.
What is the difference between ideal weight and healthy weight?
Ideal weight is a formula-based single reference number; healthy weight is a BMI-based range. The first answers "what does the formula estimate?", the second "what weight range matches the healthy BMI band?".
What is the difference between ideal weight and body fat?
Ideal weight is a target-style reference number from height; body fat percentage estimates the share of your weight that is fat. Two people at the same ideal weight can have very different composition.
Can children use an adult ideal weight calculator?
No. These adult formulas shouldn't be applied to children and teens, who are assessed with BMI-for-age percentiles. Use a child BMI calculator instead.
Can pregnant people use an ideal weight calculator?
Pregnancy weight is assessed with pregnancy-specific clinical guidance, not an IBW formula. Talk with a healthcare professional about weight during pregnancy.
Should I try to reach my calculated ideal weight?
Not automatically. The number is a formula estimate, not a personalised goal, and it ignores muscle, composition, and health context. Discuss any weight goal with a professional.
What is the difference between ideal body weight and adjusted body weight?
Ideal body weight is a height-based reference; adjusted body weight modifies it using a further formula for specific clinical or nutrition contexts. They're different calculations and not interchangeable.
This calculator implements four published ideal-body-weight equations. Each uses a base weight at 5 feet of height plus a per-inch increment above 5 feet, with sex-specific coefficients: Devine (1974) 50/45.5 kg + 2.3 kg/in; Robinson (1983) 52/49 kg + 1.9/1.7 kg/in; Miller (1983) 56.2/53.1 kg + 1.41/1.36 kg/in; Hamwi (1964) 106/100 lb + 6/5 lb/in, converted to kg. Below 5 feet, the increment is not applied (base weight only). Internal calculations are unrounded; only displayed weights are rounded. This tool is for adults; children and teens use BMI-for-age.
Authoritative references to verify before publishing:
Devine BJ (1974); Robinson JD et al. (1983); Miller DR et al. (1983); Hamwi GJ (1964) — original ideal-body-weight equations
Peer-reviewed comparisons of IBW formulas documenting that results differ between equations (e.g. Pai & Paloucek, Ann Pharmacother)
Centers for Disease Control and Prevention — About Adult BMI and BMI for Children and Teens (cdc.gov)
Author: the CalculatorSearch team. Add a medical-review block only if a genuinely qualified reviewer has checked this content — do not publish the placeholder byline as a real reviewer. Content last reviewed: August 2026.
Privacy
Your height, sex, and any weight you enter are used only to calculate results in your browser. This calculator doesn't require an account, doesn't store your inputs, and doesn't place your details in the page URL.
Medical disclaimer. This calculator provides a formula-based reference weight estimate from your height and sex. It is not a diagnosis, a personalised medical target, or a treatment recommendation, and it doesn't account for body composition or individual health. The difference between your current weight and a formula estimate does not establish a medical need to lose or gain weight. For personal guidance, talk with a qualified healthcare professional.