Ideal Weight Calculator
A healthy target weight for your height
Get an ideal body weight estimate for your height, plus the full healthy weight range based on a normal BMI.
"Ideal weight" was invented for drug dosing
This is the context that changes how you should read the number. Formulas like Devine were not developed as health or fitness targets — Devine published his in 1974 specifically to calculate gentamicin doses, an antibiotic that needs dosing on lean mass rather than total weight. It was a clinical convenience, and by his own account largely a rule of thumb.
Devine: 50 kg (men) or 45.5 kg (women), plus 2.3 kg for every inch over 5 feet.
It uses height and sex and nothing else. It cannot see muscle, frame, age or body composition, and it was never validated as a target anyone should aim at. Treat the single figure as a reference point, and the range below as the more meaningful output.
The formula figure against the healthy range
| Height | Devine (men) | Devine (women) | Healthy BMI range |
|---|---|---|---|
| 5′0″ | 110 lb | 100 lb | 95 to 128 lb |
| 5′4″ | 131 lb | 121 lb | 108 to 145 lb |
| 5′8″ | 151 lb | 141 lb | 122 to 164 lb |
| 5′10″ | 161 lb | 151 lb | 129 to 174 lb |
| 6′0″ | 171 lb | 161 lb | 136 to 184 lb |
| 6′4″ | 191 lb | 181 lb | 152 to 205 lb |
Two things stand out. The Devine figure always sits comfortably inside the healthy range rather than at its centre, and the healthy range is identical for men and women at a given height because BMI thresholds do not vary by sex — while Devine differs by 10 lb. Neither convention is more correct; they were built for different purposes.
The range is also wide. At 5′10″ it spans 45 pounds, and that width is the honest answer: a healthy weight is a band, not a point.
The competing formulas disagree
| Formula | Year | Result |
|---|---|---|
| Hamwi | 1964 | 166 lb |
| Devine | 1974 | 161 lb |
| Robinson | 1983 | 156 lb |
| Miller | 1983 | 155 lb |
An 11-pound spread between four published formulas for the same person is a reasonable measure of how much precision any of them deserve. They differ because each was fitted to different data for different clinical purposes, not because one discovered a truer answer.
What the number cannot account for
- Muscle mass. A trained person can sit well above their "ideal" weight with low body fat. The formula has no way to know.
- Frame size. Wrist and shoulder width vary considerably at the same height, and neither appears in any of these equations.
- Age. Body composition shifts through life at stable weight.
- Where fat sits. Two people at identical weight can carry very different metabolic risk.
If your interest is body composition rather than a scale reading, the body fat calculator answers a more useful question, and waist-to-height ratio — keeping your waist under half your height — captures abdominal fat that no weight-for-height formula can see.
A more useful way to use this
Treat the range as a sanity check rather than a goal. If you are inside it, weight is probably not the most informative thing to optimise. If you are outside it, that is worth a conversation with a clinician who can look at the rest of the picture.
Within the range, where you feel and perform best is individual and not something a formula from 1974 can tell you. Strength, energy, sleep and how clothes fit over months are all better signals than a target weight, and none of them require you to hit a specific number on a scale.
General information, not medical advice. Weight is one of many health signals and is best interpreted by a clinician alongside the others.
How this ideal weight calculator works out its numbers
Two figures are reported. The Devine formula gives 50 kg (men) or 45.5 kg (women) plus 2.3 kg per inch over 5 feet, converted to pounds. The healthy range converts BMI 18.5 and 24.9 back to weights at your height.
- Devine was designed for drug dosing, published in 1974 for gentamicin, which is dosed on lean mass. It was never developed or validated as a health or fitness target.
- Height and sex only. Neither figure accounts for muscle mass, frame size, age, or fat distribution.
- The healthy range does not vary by sex, because BMI thresholds do not. Devine does, by 10 lb, which is a difference in convention rather than in evidence.
- Other formulas give different answers. Hamwi, Robinson and Miller span about 11 lb for the same person, which is a fair indication of the precision available.
- Not medical advice, and not applicable to children, adolescents or pregnancy.
Reviewed September 2026.
Figures reviewed . Every worked example on this page is checked against the calculator above.
Ideal Weight Calculator: frequently asked questions
What should I weigh for my height?
There is no single answer. At 5'10" the healthy BMI range is roughly 129 to 174 lb, a 45-pound band. The Devine figure of 161 lb for men is one reference point inside it, not a target.
Where does the Devine ideal weight formula come from?
Devine published it in 1974 to calculate doses of gentamicin, an antibiotic dosed on lean mass. It was a clinical convenience, largely a rule of thumb, and was never validated as a health or fitness target.
How is ideal body weight calculated?
The Devine formula is 50 kg for men or 45.5 kg for women, plus 2.3 kg per inch over 5 feet. It uses height and sex only and cannot account for muscle, frame or body composition.
Why do ideal weight formulas disagree?
Because each was fitted to different data for different clinical purposes. For a 5'10" man, Hamwi gives 166 lb, Devine 161, Robinson 156 and Miller 155 — an 11-pound spread that indicates how much precision they deserve.
Is ideal body weight the same as a healthy weight?
No. Ideal body weight is a single formula-derived figure; a healthy weight is the broader BMI 18.5 to 24.9 range for your height. The range is the more meaningful output, and it is wide.
Is muscle accounted for?
No. Like BMI, these formulas use only height and sex, so a well-trained person can sit above their calculated ideal weight while carrying low body fat. Body fat percentage answers that question better.
Why is the healthy range the same for men and women?
Because BMI thresholds do not vary by sex, so the 18.5 to 24.9 range converts to the same weights at a given height. The Devine figure does differ by 10 lb — the two conventions were built for different purposes.
Should I aim for my ideal body weight?
Not as a target in itself. If you are inside the healthy range, weight is probably not the most informative thing to optimise. If you are outside it, that is worth discussing with a clinician who can see the rest of the picture.