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Ideal weight calculator, with honest caveats

Short answer

The best-known "ideal weight" formulas add a fixed amount per inch over 5 feet. For a man of 175 cm, Devine gives 70.5 kg and the four classic formulas span 68.1–72.0 kg. They were made to dose medicines, not to tell you what to weigh. The BMI healthy-weight range at that height, 56.7–76.3 kg, is a far wider and more honest band.

Last reviewed 27 October 20263 published sourcesNot medical advice

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Ideal weight calculator

The four classic formulas, side by side with the BMI healthy-weight range. For adults 5 ft (152 cm) and taller.

Units
Sex
cm

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Where the formulas come from

Devine published his equation in 1974 to dose the antibiotic gentamicin: 50 kg for men and 45.5 kg for women, plus 2.3 kg per inch over 5 feet. Hamwi's 1964 rule (48 kg + 2.7 kg per inch for men, 45.5 kg + 2.2 kg for women) and Miller's 1983 version (56.2 kg + 1.41 kg, 53.1 kg + 1.36 kg) come from the same height-weight tables (Pai & Paloucek, 2000).

Robinson et al. fitted median weights from the Metropolitan Life tables: 51.65 kg + 1.85 kg per inch for men and 48.67 kg + 1.65 kg for women (Robinson et al., 1983).

Range of the four formulas by height
HeightMenWomenBMI 18.5–24.9
155 cm (5 ft 1 in)50.8–57.6 kg47.8–54.5 kg44.4–59.8 kg
160 cm (5 ft 3 in)56.1–60.4 kg52.1–57.2 kg47.4–63.7 kg
165 cm (5 ft 5 in)60.8–63.2 kg56.4–59.8 kg50.4–67.8 kg
170 cm (5 ft 7 in)64.5–66.7 kg60.1–62.5 kg53.5–72.0 kg
175 cm (5 ft 9 in)68.1–72.0 kg63.4–66.0 kg56.7–76.3 kg
180 cm (5 ft 11 in)71.5–77.3 kg66.6–70.5 kg59.9–80.7 kg
185 cm (6 ft 1 in)74.3–82.7 kg69.8–75.0 kg63.3–85.2 kg
190 cm (6 ft 3 in)77.1–88.0 kg73.1–79.5 kg66.8–89.9 kg
Lowest to highest of Devine, Robinson, Miller and Hamwi, worked out from each equation. The BMI band is NICE's healthy-weight range.

Why none of them is a goal

The formulas ignore muscle, frame size, age and where you carry fat. NICE uses BMI only as a first check and recommends measuring waist-to-height ratio too (NICE NG246, 2025).

See where you sit with the BMI calculator and the waist-to-height ratio calculator. If you want to change weight, the calorie deficit calculator shows a realistic timeline.

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Common questions

Which ideal weight formula is right?

None is right for setting a personal goal. Pai and Paloucek traced all of them back to old insurance height-weight tables and found they are similar because those tables agreed with each other, concluding any one of them may be used to estimate ideal body weight for drug dosing.

Why do the formulas start at 5 feet?

Each one is a base weight at 5 ft (152.4 cm) plus a fixed amount for every inch above it. They were not designed for shorter adults, so the calculator only works from 5 ft up.

What should I use instead?

The BMI healthy-weight band (18.5–24.9, or 18.5–22.9 with NICE's lower thresholds for people of Asian, Black and Middle Eastern background) gives a range rather than a single number, and waist-to-height ratio says more about health risk than weight does.

Sources

Figures on this page were checked against these publications on 27 October 2026.

  1. Pai MP, Paloucek FP. The origin of the “ideal” body weight equations. Annals of Pharmacotherapy. 2000;34(9):1066–1069. doi.org/10.1345/aph.19381
  2. Robinson JD, Lupkiewicz SM, Palenik L, Lopez LM, Ariet M. Determination of ideal body weight for drug dosage calculations. American Journal of Hospital Pharmacy. 1983;40(6):1016–1019. doi.org/10.1093/ajhp/40.6.1016
  3. National Institute for Health and Care Excellence. Overweight and obesity management (NG246). Section 1.9: Identifying and assessing overweight, obesity and central adiposity. 2025. www.nice.org.uk/guidance/ng246/chapter/Identifying-and-assessing-overweight-obesity-and-central-adiposity

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