Ideal Weight Calculator
Compare seven height-based reference formulas, including Peterson, Devine, Robinson and Miller. The results are formula estimates, not a single medically correct or personally ideal body weight.
| Formula | Estimated reference weight |
|---|---|
| Peterson (2016) | 63.8 kg |
| Miller (1983) | 66.0 kg |
| Robinson (1983) | 65.2 kg |
| Devine (1974) | 65.9 kg |
| Hamwi (1964) | 66.7 kg |
| Broca (1871) | 70.0 kg |
| Lorentz (1929) | 65.0 kg |
Reference estimate only. These height-based formulas do not determine a person's healthy, ideal or medically appropriate weight. They do not account for body composition, muscle mass, age, ethnicity, pregnancy, health conditions or personal goals.
For general information only. This calculator does not diagnose a health condition or replace advice from a qualified healthcare professional. The height-based adult formulas are not designed for children or teenagers — for a child or young person's growth or weight concerns, speak with a GP, school nurse or another qualified health professional.
How to use this calculator
- Choose the sex to use for the calculation — most of the formulas use different constants for men and women.
- Enter your height, and pick its unit — centimetres, metres, feet, inches, or feet and inches.
- Pick the unit the estimates are shown in — kilograms, pounds, or stones and pounds.
- Read the comparison range across all seven formulas, the arithmetic average beside it, and each individual formula's estimate in the table below.
Nothing is submitted anywhere. The calculation runs in the page as you type, and the link in your address bar carries your figures, so it can be shared or bookmarked.
How the comparison works
Different ideal-body-weight formulas can produce different results for the same height. This calculator shows the individual estimates rather than treating one formula as definitive. The range and average summarise the methods shown; neither is a medical recommendation or a personal target.
- Each estimate is calculated independently using one of seven height-based formulas.
- The displayed range is the lowest to the highest of the seven estimates: min(F₁, …, F₇) to max(F₁, …, F₇).
- The displayed average is the arithmetic average of those seven estimates — (F₁ + F₂ + F₃ + F₄ + F₅ + F₆ + F₇) ÷ 7 — not a clinical recommendation.
- Formula estimates differ because the equations were developed from different populations, assumptions and historical datasets.
- Body composition and personal circumstances — muscle mass, frame size, age, ethnicity, health conditions — are not captured by any height-only method.
All seven formulas are defined for every height this calculator accepts (130–220 cm), so the average is always taken over seven values. Estimates are calculated internally in kilograms and then converted to the unit you choose; the range, the average and each row are rounded for display using the site's normal weight-rounding (one decimal place for kilograms, whole pounds, whole stones and pounds).
What are the seven formulas?
Hamwi, Devine, Robinson and Miller share the same shape: a base weight at exactly 5 feet (60 inches) tall, plus a fixed amount of weight for every inch above that.
- Base weight and per-inch amount — the constants in the table below, by sex.
- Height in inches − 60 — how many inches taller than 5 ft the height is.
Peterson works differently: it targets a fixed BMI of 22 regardless of sex. Broca is height alone with no correction — this is the original 1871 version; some later adaptations reduce the female figure by 10%, which this calculator does not apply. Lorentz applies a small sex-specific correction to Broca's figure once height passes 150 cm.
- Lorentz divisor — 4 for men, 2 for women, and 0 correction at or below 150 cm.
| Formula | Published | Men | Women |
|---|---|---|---|
| Peterson | 2016 | Same for both sexes | Same for both sexes |
| Miller | 1983 | 56.2 + 1.41 kg per inch | 53.1 + 1.36 kg per inch |
| Robinson | 1983 | 52 + 1.9 kg per inch | 49 + 1.7 kg per inch |
| Devine | 1974 | 50 + 2.3 kg per inch | 45.5 + 2.3 kg per inch |
| Hamwi | 1964 | 48 + 2.7 kg per inch | 45.5 + 2.2 kg per inch |
| Broca | 1871 | Same for both sexes | Same for both sexes |
| Lorentz | 1929 | Correction ÷ 4 above 150 cm | Correction ÷ 2 above 150 cm |
Worked example. A man 175 cm tall (68.9 inches, 8.9 inches over 5 ft) gets Peterson 67.7 kg, Miller 68.7 kg, Robinson 68.9 kg, Devine 70.5 kg, Hamwi 72.0 kg, Broca 75.0 kg and Lorentz 68.8 kg — a comparison range of 67.7–75.0 kg and an arithmetic average of 70.2 kg.
Limitations of formula-based ideal weight
- Uses only height and sex — it does not account for muscle mass, frame size or age.
- Designed for adults aged 18 and over. None of the seven formulas were derived from children's or teenagers' growth data, and none apply during pregnancy.
- Built for clinical and historical reference use, such as drug dosing, rather than as a fitness or health target.
- It is not a diagnosis, a body-composition assessment or medical advice, and no figure it produces is a safe, optimal, recommended or target weight.
For a range-based view of a healthy weight at your height, use the BMI calculator. For an estimate that accounts for body composition rather than height alone, use the body fat percentage calculator.