How is ideal body weight calculated?

Each formula starts from a base weight for someone exactly 5 feet tall and adds a fixed amount for every inch above that. The Devine formula (1974), for example, starts at 50 kg for men and 45.5 kg for women, then adds 2.3 kg per inch over 5 feet. Robinson, Miller, and Hamwi use the same base-plus-slope shape with different constants.

What is the Devine formula?

Devine's formula was published by Dr. B. J. Devine in 1974 as a quick way to estimate lean body weight for dosing certain medications. It's the most commonly cited ideal-weight formula in clinical settings: 50 + 2.3 × (inches over 5 ft) for men, 45.5 + 2.3 × (inches over 5 ft) for women, in kilograms.

What should a 5'10" male weigh?

For a male at 5'10" (70 in), the Devine formula gives about 73 kg (160.9 lb); Robinson, Miller, and Hamwi land within a few kilograms of that. The healthy-BMI weight range for that height is roughly 129–174 lb.

What should a 5'4" female weigh?

For a female at 5'4" (64 in), the Devine formula gives about 54.7 kg (120.6 lb), with Robinson, Miller, and Hamwi close behind. The healthy-BMI weight range for that height is roughly 108–145 lb.

Which ideal weight formula is most accurate?

None of the four is more "correct" than the others — they were each fitted to different reference groups decades apart. Devine (1974) is the one most often used clinically because it's simple and became the default for drug-dosing calculations; Robinson (1983) and Miller (1983) were later attempts to refit the data; Hamwi (1964) is the oldest and simplest. All four are estimates, not measurements.

Does ideal weight account for muscle?

No. Every formula here uses only height and sex, so it can't tell a heavily muscled person from someone carrying the same weight in fat. A muscular athlete will often sit well above every formula's number without being overweight — frame size and body composition matter more than these formulas can capture.

Ideal weight vs BMI — what's the difference?

Ideal body weight formulas output a single target weight from your height. BMI instead scores a given height-and-weight pair into a category (underweight, normal, overweight, obese) using a range, not a point. This calculator shows both: a point estimate from each formula, and the healthy-BMI weight range for context.

Health

Ideal Weight Calculator

Enter your sex and height to see ideal body weight from the Devine, Robinson, Miller, and Hamwi formulas, plus the healthy BMI weight range for your height — updating as you type.

Your details

Sex and height are the only inputs every formula uses.

Sex

Height

These are population averages for adults of average build. They are a starting reference, not a personal target — they don't account for frame size, muscle mass, age, or body composition. Check with a doctor or dietitian before using a number here to set a goal.

Ideal weight · Devine formula

160.9

Male · 5 ft 10 in (5′10″)

Robinson

156.5 lb

Miller

155 lb

Hamwi

165.3 lb

Healthy BMI range (18.5–24.9)

129–173.5 lb

Not a personal target: these are population estimates from height and sex alone — they ignore frame size, muscle mass, age, and body composition. Talk to a doctor or dietitian before using any of these numbers as a goal.

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The basics

What ideal body weight is

Ideal body weight (IBW) formulas turn a height and a sex into a single reference weight. The formula for weight is 50 + 2.3 × (inches over 5 ft) in kilograms for men, using the Devine method — the version most often cited in clinical settings. They were built to estimate lean body weight for medication dosing, not to define what any one person should weigh.

A reference weight, not a target

Every formula on this page outputs a single number from height and sex alone. It is a starting reference for comparison, similar to a shoe-size chart — useful for a population, approximate for an individual.

The base-height rule

All four formulas share the same shape: a fixed base weight for someone exactly five feet tall, plus a fixed amount added for every inch taller than that. Only the base and the per-inch amount differ between them.

Method

Work out the Devine formula by hand

Four steps, using the most widely cited of the four formulas.

1
Convert height to inches
Turn feet and inches into one number of total inches.
5 ft 10 in → 70 in
2
Find inches over 5 ft
Subtract 60 (five feet) from the total. Anything below zero is floored at zero.
70 − 60 = 10 in
3
Apply the formula
Add the per-inch amount, multiplied by inches over 5 ft, to the base weight for the sex.
50 + 2.3 × 10 = 73 kg
4
Convert to pounds
Multiply the kilogram result by the conversion factor.
73 × 2.2046226 ≈ 160.9 lb

Worked examples

See each formula on the same person

Same height, same sex, four formulas — switch tabs to see how the base weight and the per-inch slope change the result.

Example: a male at 5'10" (70 in), 10 in over the 5 ft baseline.

Given — base 50 kg, slope 2.3 kg per inch over 5 ft

Multiply — 2.3 × 10 = 23

Evaluate — 50 + 23 = 73 kg

Devine (1974): 73 kg ≈ 160.9 lb

Where it shows up

Why ideal weight formulas exist

Built for clinical shorthand, they now show up well beyond the hospital.

mg per kg of IBW

Drug dosing

Some medications are dosed by lean body weight rather than total weight, so clinicians use a formula like Devine’s as a fast stand-in when a direct measurement isn't available.

a rough target

Fitness goals

People setting a weight-loss or bulking goal often start from an ideal-weight number as a sanity check, then adjust for frame size and how much muscle they carry.

a first data point

Clinical baselines

A quick reference weight helps a clinician spot whether a patient's weight looks unusual for their height before ordering more detailed body-composition testing.

Reference

Ideal weight by height, all four formulas

Every formula's estimate, in pounds, for a range of common heights — men and women side by side.

Height	Devine M	Robinson M	Miller M	Hamwi M	Devine F	Robinson F	Miller F	Hamwi F
5′0″ (152 cm)	110 lb	115 lb	124 lb	106 lb	100 lb	108 lb	117 lb	100 lb
5′2″ (157 cm)	120 lb	123 lb	130 lb	118 lb	110 lb	116 lb	123 lb	110 lb
5′4″ (163 cm)	131 lb	131 lb	136 lb	130 lb	121 lb	123 lb	129 lb	120 lb
5′6″ (168 cm)	141 lb	140 lb	143 lb	142 lb	131 lb	131 lb	135 lb	129 lb
5′8″ (173 cm)	151 lb	148 lb	149 lb	153 lb	141 lb	138 lb	141 lb	139 lb
5′10″ (178 cm)	161 lb	157 lb	155 lb	165 lb	151 lb	146 lb	147 lb	149 lb
6′0″ (183 cm)	171 lb	165 lb	161 lb	177 lb	161 lb	153 lb	153 lb	159 lb
6′2″ (188 cm)	181 lb	173 lb	167 lb	189 lb	171 lb	160 lb	159 lb	168 lb
6′4″ (193 cm)	191 lb	182 lb	174 lb	201 lb	181 lb	168 lb	165 lb	178 lb

Worth knowing

Limits of an ideal-weight number

Four things every one of these formulas leaves out.

height only

Frame size isn't in the formula

A person with a naturally larger or smaller skeletal frame will sit above or below every formula's number without being over- or underweight. None of the four formulas ask about wrist or elbow measurements the way older frame-size charts did.

not a diagnosis

These are population estimates

Each formula was fitted to a specific reference group decades ago. They describe an average, not a verdict on any individual — treat a result outside the band as a prompt to ask a professional, not a conclusion on its own.

lean vs total

Athletes run high on purpose

A muscular or athletic person will typically weigh more than every formula suggests, because none of them separate muscle from fat. A high result next to a low body-fat percentage is not a problem.

a snapshot, not a plan

Age and life stage change the picture

These formulas were derived from adult populations and don't adjust for older adults, pregnancy, or growing children — each of those groups is better served by a clinician-guided target than any of the four numbers here.

Quick chart

Ideal weight lookup, by height

The Devine formula's estimate for men and women, plus the healthy-BMI weight range, across a full run of heights.

Height	Male (Devine)	Female (Devine)	Healthy BMI range
4′10″	110 lb	100 lb	89–119 lb
4′11″	110 lb	100 lb	91–123 lb
5′0″	110 lb	100 lb	95–127 lb
5′1″	115 lb	105 lb	98–132 lb
5′2″	120 lb	110 lb	101–136 lb
5′3″	125 lb	116 lb	104–141 lb
5′4″	131 lb	121 lb	108–145 lb
5′5″	136 lb	126 lb	111–150 lb
5′6″	141 lb	131 lb	115–154 lb
5′7″	146 lb	136 lb	118–159 lb
5′8″	151 lb	141 lb	122–164 lb
5′9″	156 lb	146 lb	125–169 lb
5′10″	161 lb	151 lb	129–174 lb
5′11″	166 lb	156 lb	133–179 lb
6′0″	171 lb	161 lb	136–184 lb
6′1″	176 lb	166 lb	140–189 lb
6′2″	181 lb	171 lb	144–194 lb
6′3″	186 lb	176 lb	148–199 lb
6′4″	191 lb	181 lb	152–205 lb
6′5″	196 lb	187 lb	156–210 lb
6′6″	202 lb	192 lb	160–215 lb

Which formula to use

Four formulas, four decades

Each formula is cited here with its original author and publication year, since the numbers only mean something in that context.

Devine (1974): Published by Dr. B. J. Devine as a dosing shortcut. The simplest and most widely used formula today, especially in pharmacy and clinical calculators.
Robinson (1983): A re-fit of Devine's approach against a different patient dataset, giving a slightly lower per-inch slope for women.
Miller (1983): Published the same year as Robinson, with a higher base weight and a gentler slope — it tends to sit closest to the healthy-BMI midpoint at average heights.
Hamwi (1964): The oldest of the four, originally written as a quick bedside rule of thumb for diabetes management before calculators were common.

FAQ

Common questions

There is no single correct number — four widely used formulas (Devine, Robinson, Miller, and Hamwi) each give a slightly different estimate from your height and sex, and this calculator shows all four side by side along with the healthy-BMI weight range for your height. Treat the spread between them as your reference band, not one exact target.

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