How to use it
- Choose Metric or Imperial, then select your Sex.
- Enter your Height, or the feet and inches if you chose imperial.
- Read the Healthy weight range first, then the ideal weight from each formula in the table.
How the ideal weight formulas work
The four formulas start from a base weight and add a fixed amount for each inch of height above 5 feet (152.4 cm). They were published in 1964 (Hamwi), 1974 (Devine) and 1983 (Robinson and Miller), and each was based on a different group of people.
These figures are estimates for information only. They are not medical advice: a healthy weight depends on body composition, age, health and medicines, so talk to a doctor before you set a target weight.
Devine (1974) men 50 + 2.3 x inches over 5 ft; women 45.5 + 2.3 x inches over 5 ft (kg)
Robinson (1983) men 51.65 + 1.85 x inches over 5 ft; women 48.67 + 1.65 x inches over 5 ft (kg)
Miller (1983) men 56.2 + 1.41 x inches over 5 ft; women 53.1 + 1.36 x inches over 5 ft (kg)
Hamwi (1964) men 106 + 6 x inches over 5 ft; women 100 + 5 x inches over 5 ft (lb)The healthy weight range
The range is the weight at a body mass index (BMI) of 18.5 and of 24.9: the BMI is the weight in kilograms divided by the height in metres squared, so the range is 18.5 and 24.9 times the height in metres squared. The World Health Organization describes a BMI of 25 or more as overweight and 30 or more as obesity.
This page gives the weight range for your height. It does not calculate your own BMI, and it does not measure body fat, so a muscular person can weigh more than the range and be healthy.
Limits of the formulas
- The formulas use height above 5 feet. For shorter people the table is hidden and only the range is shown.
- The Devine formula is linked to drug dosing in secondary sources, and the Robinson paper is titled for drug dosage calculations. None of the four is a health target.
- The originals of the Devine and Miller formulas are not freely available. Their constants here are taken from secondary references, which the review by Pai and Paloucek discusses.
Worked example: man, 175 cm
175 cm is 68.9 inches, which is 8.9 inches above 5 feet. The healthy range is 18.5 x 1.75 x 1.75 = 56.7 kg to 24.9 x 1.75 x 1.75 = 76.3 kg.
Devine gives 50 + 2.3 x 8.9 = 70.5 kg, Robinson 51.65 + 1.85 x 8.9 = 68.1 kg, Miller 56.2 + 1.41 x 8.9 = 68.7 kg, and Hamwi 106 + 6 x 8.9 = 159.4 lb, which is 72.3 kg.
| Formula | Weight |
|---|---|
| Healthy range (BMI 18.5 to 24.9) | 56.7 - 76.3 kg |
| Devine (1974) | 70.5 kg |
| Robinson (1983) | 68.1 kg |
| Miller (1983) | 68.7 kg |
| Hamwi (1964) | 72.3 kg |
Frequently asked questions
Is there one correct ideal weight?
No. The four formulas give different answers because each was fitted to different groups, so a range is a more honest guide than one number.
Why is the healthy range based on a BMI of 18.5 to 24.9?
The World Health Organization describes a BMI of 25 or more as overweight and 30 or more as obesity, so 24.9 is the top of the healthy band. The lower end is the usual cut-off for underweight.
Why is the table hidden for a short height?
The formulas count inches above 5 feet (152.4 cm). Below that height they give figures outside the range their authors used, so the table is hidden and the healthy range is still shown.
Are these formulas used for drug doses?
Some were made for drug dosing calculations. This page gives no dosing advice; ask a pharmacist or doctor about any dose.
Does the calculator store my height or weight?
No. The figures are calculated in your browser and nothing you enter is sent to us.
Sources
- Robinson JD et al. 1983, Am J Hosp Pharm: ideal body weight for drug dosage calculations (PubMed)
- Miller DR 1983, Am J Hosp Pharm: Determining ideal body weight (PubMed record)
- Pai MP, Paloucek FP 2000, Ann Pharmacother: the origin of the ideal body weight equations (PubMed)
- World Health Organization: Obesity and overweight fact sheet
Figures and text last checked on Tuesday, November 10, 2026.