Ideal Weight Calculator
Compare the four ideal body weight formulas side by side, and see the healthy weight range for your height — in pounds or kilograms.
These formulas start from a base weight at 5 feet and add a fixed amount per inch above it, so they cannot report a figure below 5 feet (152.4 cm).
| Formula | Ideal weight |
|---|
Each formula was published for a different purpose and they disagree by a few pounds, which is the honest picture. The healthy BMI range is the wider band the four estimates sit inside.
| Formula | Men | Women |
|---|---|---|
| Hamwi (1964) | 48.0 + 2.7/in | 45.5 + 2.2/in |
| Devine (1974) | 50.0 + 2.3/in | 45.5 + 2.3/in |
| Robinson (1983) | 52.0 + 1.9/in | 49.0 + 1.7/in |
| Miller (1983) | 56.2 + 1.41/in | 53.1 + 1.36/in |
Kilograms at 5 feet, plus the stated amount for every inch above. Devine is the one most often used clinically, and all four began as drug-dosing tools rather than fitness targets.
| Who | Small | Large |
|---|---|---|
| Women under 5′2″ | wrist < 5.5″ | > 5.75″ |
| Women 5′2″ – 5′5″ | wrist < 6″ | > 6.25″ |
| Women over 5′5″ | wrist < 6.25″ | > 6.5″ |
| Men over 5′5″ | wrist < 6.5″ | > 7.5″ |
None of the four formulas takes frame into account. Measure your wrist against these bands: a large-framed person carrying the same amount of fat will sit above their calculated figure, and a small-framed person below it, without either being a problem.
Where "ideal weight" actually came from
Not from fitness, and not from health. Every formula on this page was written to help work out drug doses.
The problem clinicians faced was that many medicines distribute through lean tissue rather than fat, so dosing by total body weight overshoots in a heavier patient. G. J. Hamwi published a quick rule in 1964 to estimate a weight that better tracked lean mass, and B. J. Devine followed in 1974 with a version that became the standard. J. D. Robinson and D. R. Miller each refined Devine's numbers in 1983. Only later did the phrase escape into diet culture, where it acquired a meaning none of its authors intended.
That history is the single most useful thing to know before reading your result. These are not statements about how you should look or what you should weigh to be healthy. They are rough population averages, built for a different job, that happen to be easy to calculate.
How this calculator works
All four formulas share one shape: a base weight in kilograms at exactly five feet, plus a fixed increment for every inch above that.
Robinson · men 52.0 + 1.9/in · women 49.0 + 1.7/in
Miller · men 56.2 + 1.41/in · women 53.1 + 1.36/in
Devine · men 50.0 + 2.3/in · women 45.5 + 2.3/in
Hamwi · men 48.0 + 2.7/in · women 45.5 + 2.2/in
A man of 5′10″ is ten inches over the baseline, so Devine gives 50.0 + 23.0 = 73.0 kg, or about 161 lb. The same height through Robinson gives 71.0 kg and through Hamwi 75.0 kg — a spread of roughly nine pounds from the same input.
The healthy BMI range is calculated separately and is not a formula output at all. For anyone 21 or over it is the WHO band of BMI 18.5 to 25 applied to your height. Under 21 it switches to CDC growth-chart percentiles for that age and sex, because a growing body is assessed against others the same age rather than against a fixed adult number.
Why the four formulas disagree
They were fitted to different data by people asking slightly different questions, and none of them was ever meant to be definitive. The disagreement is not a flaw to resolve — it is the most honest signal on the page.
Hamwi (1964) is the oldest and has the steepest increment for men at 2.7 kg per inch, so it reads highest for tall men. Devine (1974) softened that to 2.3 kg and is the version most clinical references still use. Robinson (1983) and Miller (1983) both adjusted Devine downward for taller people; Miller has the gentlest slope of all, at 1.41 kg per inch for men, which makes it the most forgiving formula at height and the least at the short end.
The practical reading: if all four cluster tightly, your height sits near the middle of the range they were fitted on. If they spread widely, you are toward one end and the numbers deserve correspondingly less weight.
The healthy range matters more than the number
A single ideal weight implies a precision that does not exist. The healthy BMI band is the more useful output, and it is deliberately wide — for a 5′10″ adult it runs from about 129 to 174 lb, a spread of 45 lb, and every point inside it is compatible with good health.
That width is not vagueness. It reflects genuine variation between people of the same height in bone density, frame, muscle mass and where they carry fat. Two people at opposite ends of that band can both be perfectly healthy, and moving from one end to the other is not automatically an improvement in either direction.
If you want a sharper picture than height alone can give, body composition is the thing to measure. The body fat calculator estimates it from a tape measure, and the lean body mass calculator separates the part of your weight that these formulas were originally trying to approximate.
Frame size, muscle and everything the formulas miss
Height and sex are the only inputs. Everything else that determines a reasonable weight is invisible to them.
Frame size is the most measurable of the omissions. It is usually judged from wrist circumference relative to height, and the bands are in the card beside the calculator. A large-framed adult carries more bone and connective tissue and will sit above their calculated figure at identical body fat; a small-framed one below it.
Muscle is the omission that causes the most confusion. Muscle is denser than fat, so a trained person routinely reads as above their ideal weight while carrying less fat than someone at the "correct" number. This is the same weakness BMI has, for the same reason.
Age matters too, and not in the way people expect. Adults lose height gradually — an inch and a half to two inches by seventy is typical — which quietly lowers a calculated ideal weight over the years while lean mass is also declining. Neither change means the earlier figure was wrong.
What this calculator does not cover
- Anything below 5 feet. The formulas define a base at exactly five feet and build upward. Below that there is nothing to build on, so no figure is produced.
- Body composition. Height and sex go in; muscle, bone and fat are all invisible to the arithmetic.
- Children as individuals. The healthy band under 21 comes from population percentiles, which describe where a child sits among peers, not whether that position is right for them. Growth is a conversation for a paediatrician.
- Pregnancy. Weight gain during pregnancy follows its own guidance entirely, and nothing here applies.
- Athletes and unusual builds. The further your body composition sits from average, the less any of these four numbers means.
- What to do about it. This page produces a reference point, not a plan. If you want to change your weight, the TDEE calculator deals with the energy side.
If a number here worries you, or you are making decisions about your health from it, take it to a doctor or a registered dietitian rather than acting on it alone.
Frequently asked questions
How much should I weigh for my height?
There is no single answer, which is why this page shows four figures rather than one. The Robinson, Miller, Devine and Hamwi formulas each give a slightly different number for the same height, and the healthy BMI range is a band roughly twenty pounds wide. Anywhere inside that band is reasonable; where you sit within it depends on frame, muscle and things no formula can see.
Which ideal weight formula is the most accurate?
None of them is accurate in the way the word suggests, because none was built to describe health. Devine is the one most often used clinically and has become the default reference. Robinson and Miller were later adjustments of it. Hamwi is the oldest and tends to read highest for men. Treat the spread between them as the honest margin of error rather than picking a winner.
Why does the calculator ask for my age?
Only to decide which healthy range applies. The four formulas ignore age entirely. But under 21 the healthy band comes from CDC growth-chart percentiles for that age and sex instead of the adult BMI 18.5 to 25, because growing bodies are assessed against their peers rather than a fixed number.
Why can't I enter a height under 5 feet?
Because of how the formulas are written. Each one states a base weight at exactly 5 feet and adds a fixed amount for every inch above it, so below 5 feet there is nothing to add to and the arithmetic runs backwards into meaningless territory. That is a real limitation of the formulas, not of this page.
Where did these formulas come from?
Drug dosing, not fitness. Hamwi published his in 1964 to help calculate medication doses, since the metabolism of many drugs tracks lean mass better than total weight. Devine followed in 1974 for the same reason, and Robinson and Miller refined it in 1983. They found their way into fitness advice much later, which is worth remembering before treating one as a target.
Should I actually aim for my ideal weight?
Not as a target to hit. These numbers take account of height and sex and nothing else — not frame size, not muscle, not body composition, not age. A muscular person will read as above their ideal weight while carrying very little fat. Use the figure as a rough reference point, and judge progress on how you feel, move and perform.
How does body frame size change the answer?
None of the four formulas accounts for it, which is one reason they disagree with real bodies. Frame is usually judged from wrist circumference relative to height — the table beside the calculator gives the bands. A large-framed person will naturally sit above their calculated figure and a small-framed person below it, at the same body fat percentage.
What is the difference between ideal weight and healthy weight?
Ideal weight is a single number from a formula. Healthy weight is a range, and the healthy BMI band on this page is that range for your height. The band is wide on purpose: it reflects that people of the same height can be healthy at meaningfully different weights, which a single figure cannot express.
Everything on this page is an educational estimate. It carries no clinical weight, replaces no consultation, and diagnoses nothing — and the formulas behind it were written for drug dosing rather than for describing a healthy body. Do not treat any figure here as a weight you should reach. That applies with particular force during pregnancy, for anyone under 18, alongside any diagnosed condition, and for anyone who has struggled with food or body image. Speak with a physician or a registered dietitian. Learn more about how we build these tools or read our privacy policy.