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Calculator Answers

Ideal Weight Calculator

Source: Pai MP, Paloucek FP. The origin of the ideal body weight equations. Ann Pharmacother. 2000;34(9):1066-1069 · Source verified July 22, 2026

Blake Boege
Written by Blake Boege · Founder, Calculator Answers

An ideal weight calculator estimates a healthy body weight range from height and sex using established formulas. This one runs the Hamwi, Devine, Robinson and Miller equations side by side, plus the BMI healthy range, so the spread between them is visible rather than averaged away. It takes height and sex only: there is no frame-size input, and no formula here adjusts for one.

Estimate a healthy weight range from height and sex using four standard clinical formulas — Hamwi, Devine, Robinson, and Miller — plus the BMI 18.5–25 range. We report a range across them, not a single “perfect” number.

See also: BMI Calculator, Body Fat Calculator, and BMR Calculator.

Quick Answer

Find your ideal body weight range based on your height and gender. Compare results from multiple scientific formulas including the Devine, Robinson, and Miller equations.

Sex

Units

Height
ft
in

We compute four well-known “ideal” body weight formulas plus the BMI healthy range, then report a range across them. None of these is a medical target — they were originally designed for medication-dosing or insurance tables.

Healthy weight range

Range across formulas (men)

155 lb – 165 lb

Height 5′10″ · narrow range; bodies are not formulas

Hamwi (1964)165 lb
Devine (1974)161 lb
Robinson (1983)157 lb
Miller (1983)155 lb
BMI healthy (18.5–25)129 lb – 174 lb

None of these is the “perfect” weight. They were built for clinical drug-dosing and insurance tables, not for personal health goals. Body composition, age, fitness, and individual health context matter much more than any formula.

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Examples

Man · 5′10″

≈ 155–165 lb across formulas

Woman · 5′6″

≈ 129–135 lb across formulas

Man · 178 cm

≈ 70–75 kg across formulas

Woman · 165 cm

≈ 56–60 kg across formulas

How it works

Formula · Devine: male IBW = 50 kg + 2.3 kg per inch over 5 ft; female IBW = 45.5 kg + 2.3 kg per inch over 5 ft. Robinson, Miller, and Hamwi use different baselines and increments.

What is 'ideal weight'?

'Ideal weight' is a clinical concept used in medical dosing calculations and population health benchmarks. It's NOT the same as 'goal weight' or 'attractive weight' — it's a statistical estimate of the weight at which someone of your height has the lowest health risk on average.

There's no single 'ideal' weight for any individual. Body composition matters more than total weight — a 200-lb muscular athlete and a 200-lb sedentary person have very different health profiles despite identical scale numbers. Use ideal weight as a rough reference, not a strict target.

Modern medicine increasingly uses BMI (Body Mass Index) and waist-to-hip ratio instead of ideal weight, because they account for height more accurately. Use the BMI calculator alongside this one for a more complete picture.

How the math works

Each formula is a base weight at 5 ft plus a per-inch slope above 5 ft. We evaluate all four for your sex and height, then compute the BMI 18.5–25 healthy range as a fifth reference.

men · Devine · 50.0 + 2.3 · (height_in − 60) kg

women · Devine · 45.5 + 2.3 · (height_in − 60) kg

Other formulas use the same shape with different bases and slopes: Hamwi (broader), Robinson (lighter), Miller (lightest).

We report the min and max across all four formulas as the headline range, and list each formula plus the BMI band in the breakdown.

The 4 ideal weight formulas explained

Each formula was developed for a slightly different purpose:

DEVINE FORMULA (1974): The most commonly used clinical formula, originally created for drug dosing calculations.
Men: 50 kg + 2.3 kg per inch over 5 feet
Women: 45.5 kg + 2.3 kg per inch over 5 feet

ROBINSON FORMULA (1983): A refinement of Devine, often producing slightly lower estimates.
Men: 52 kg + 1.9 kg per inch over 5 feet
Women: 49 kg + 1.7 kg per inch over 5 feet

MILLER FORMULA (1983): Generally produces the lowest estimates of the four.
Men: 56.2 kg + 1.41 kg per inch over 5 feet
Women: 53.1 kg + 1.36 kg per inch over 5 feet

HAMWI FORMULA (1964): The original, simplest formula. Still used in dietitian practice for quick estimates.
Men: 48 kg + 2.7 kg per inch over 5 feet
Women: 45.5 kg + 2.2 kg per inch over 5 feet

The four formulas typically produce results within 10-15 lbs of each other. Use the average if you want a single number, or treat them as a range.

Limitations of ideal weight formulas

All four formulas have significant limitations:

NOT ADJUSTED FOR BODY COMPOSITION: A muscular athlete may exceed 'ideal' weight while having excellent body composition. The formulas don't distinguish between muscle and fat.

NOT ADJUSTED FOR FRAME SIZE: A person with a large skeletal frame naturally weighs more than someone with a small frame at the same height. None of these formulas account for frame size.

DEVELOPED FROM LIMITED POPULATIONS: Most formulas were developed using narrow population samples (mostly white American adults). Accuracy may be lower for other ethnicities.

NOT DESIGNED FOR EXTREME HEIGHTS: Below 5'0" or above 6'5", these formulas become less accurate.

NOT A WEIGHT LOSS GOAL: Don't treat 'ideal weight' as a target for weight loss without considering body composition, fitness level, and health markers. Many people are healthiest above their formula-calculated ideal weight, especially athletes. Body fat percentage and lean body mass are more useful metrics.

Estimate, not medical advice. These formulas were built for clinical drug-dosing and insurance tables, not personal health goals. Body composition, fitness, age, and individual health context matter much more than any single number. If you have a medical condition, an eating disorder, are pregnant, or have any nutrition concern, talk to a qualified healthcare professional.

Related Calculators

More tools from Health

BMI CalculatorCompute Body Mass Index from height and weight, with the standard category scale and the healthy weight range for your height.Body Fat CalculatorEstimate body fat percentage using the U.S. Navy circumference method, with the standard fitness category scale.BMR CalculatorEstimate your Basal Metabolic Rate — the calories your body burns at rest — using the Mifflin–St Jeor equation.

Frequently asked questions

No. The four formulas we report were built for different purposes — Hamwi for nutrition tables, Devine for drug dosing, Robinson and Miller as later refinements — and they disagree by several pounds at the same height. We report a range across all four plus the BMI healthy range so you can see the spread, not pretend there's a single right answer.

Only three of the four come from the paper this page cites. Pai and Paloucek document Devine, Robinson and Miller, and the words Hamwi and Broca do not appear in it anywhere, so the Hamwi row here is attributed separately and is not covered by that source. On the three it does document, its finding is blunter than most pages admit: Devine's equations "were not referenced to a particular data set, and so created a controversy over their validity", and Robinson established through correspondence that they rested on "the empiric estimates of his mentor, Dr. Margaret McCarron". Pai's own conclusion is that "any one of these equations may be used to estimate IBW", which is worth holding against the neat spread this page prints. Hamwi (1964) was published as a quick clinical bedside calculation. Devine (1974) was developed for gentamicin antibiotic dosing — it's the standard in pharmacology. Robinson (1983) and Miller (1983) were modified versions fit on different anthropometric data. None of them was developed for personal health or fitness goals — they were clinical or actuarial tools.

BMI 18.5–25 corresponds to a kg range that depends on your height. We include it in the breakdown because it's the World Health Organization's standard healthy-weight band and lines up well with population mortality data — though it has the same limitations as BMI elsewhere (doesn't distinguish muscle from fat, doesn't apply to pregnancy or kids).

Because the formulas don't. Two people of the same height can land at the same calculated “ideal weight” while one has 12% body fat and the other has 30%. For a number that reflects body composition rather than just height, use the body-fat or BMI calculators alongside this one — and remember that body composition matters more than the bathroom scale.

They were designed at and above 5 ft, and the slope per inch was meant to apply only to inches over 60. We extrapolate downward by subtracting the same slope per inch below 60″, which is the convention most clinical references use, but accuracy degrades for very short heights — treat short-stature outputs as rough estimates only.

It depends on the use case. Clinicians most commonly use the Devine formula for drug dosing calculations. For general population health benchmarks, BMI is preferred over any ideal weight formula. For athletic individuals, body fat percentage and lean body mass are more useful than any of these formulas. Treat the formulas as a starting point, not a definitive answer.

Not necessarily. Your goal weight should reflect your personal health markers (blood pressure, cholesterol, blood sugar, fitness level) and body composition — not just a formula. Many people feel and perform best slightly above or below their calculated ideal weight. Use the ideal weight as one data point among many.

Each formula was developed using different population data and different statistical assumptions. They typically produce results within 10-15 lbs of each other. The differences reflect that 'ideal weight' is a fuzzy concept — there's no single objectively correct answer. Looking at the range of estimates is often more useful than picking one number.

Yes, slightly. BMI defines a 'healthy weight range' (18.5-24.9 BMI) based on height, allowing for a 30-40 lb range at any given height. The ideal weight formulas calculate a single point estimate. BMI is the modern standard for population health; ideal weight formulas are still used in specific clinical contexts like drug dosing.

All four formulas use height as their primary variable, adding a fixed increment for every inch above 5 feet: 2.3 kg per inch for Devine, 1.9 for Robinson, 1.41 for Miller and 2.7 for Hamwi. That is why they diverge more the further you are from 60 inches.

Significantly, and this calculator does not model it. People with large skeletal frames, meaning broader shoulders and heavier wrists and ankles, weigh more than small-framed people of the same height, and none of the four formulas here take frame size as an input. This page used to tell readers to measure their wrist and then shift the result up or down by ten percent. That instruction is gone, for two reasons. The calculator has no wrist field and applies no such adjustment, so the number on the screen never changed. And the ten percent figure is folk practice rather than something the Hamwi, Devine, Robinson or Miller papers derived or tested. Treat the spread between the four formulas as the honest measure of how imprecise a height-only estimate is.