What is my ideal weight for my height?
This ideal weight calculator shows what four well-known medical formulas — Robinson (1983), Miller (1983), Devine (1974) and Hamwi (1964) — consider the ideal body weight for your height and sex, side by side with the healthy weight range from the World Health Organization’s BMI categories.
The formulas disagree by several kilograms and the BMI range is wider still, so treat the overlap as a sensible zone, not a precise target. Add your current weight to see how far you are from the healthy range.
For clinicians and students, a second table gives the Devine ideal body weight, adjusted body weight, the ARDSNet predicted body weight and a 6–8 mL/kg tidal volume. These are reference figures, not medical advice or a personal goal; check clinical numbers against your local protocol.
How to use the Ideal Weight Calculator
- Choose metric (cm, kg) or imperial (ft, in, lb) units.
- Select male or female — each formula has separate constants for men and women.
- Enter your height. Heights under 5 ft are handled with a clear note.
- Optionally enter your current weight for your BMI and the adjusted body weight.
- Compare the formulas, the BMI range and the clinical table.
Ideal Weight Calculator features
Four formulas in one table
Robinson, Miller, Devine and Hamwi are calculated together with the equation used for each.
Healthy BMI range included
The weight range for a BMI of 18.5–24.9 at your height.
Sensible for shorter people
Below 5 ft the headline switches to the BMI range and extrapolated values are marked.
Compare with your weight
Your BMI and how much to gain or lose to reach the healthy range.
Clinical weights
Adjusted body weight, % of IBW, ARDSNet predicted body weight and tidal volume, with the usual dosing-weight convention.
Metric and imperial
Kilograms or pounds; your choice is remembered in your browser.
The ideal body weight formulas
Each formula starts from a base weight at 5 ft (152.4 cm) and adds a fixed amount for every inch above that. Hamwi was published in pounds (106 lb + 6 lb per inch for men, 100 lb + 5 lb for women); the calculator uses those exact values.
Worked example: a man who is 5 ft 10 in is 10 inches over 5 ft. Robinson gives 52 + 1.9 × 10 = 71.0 kg (157 lb); Miller 56.2 + 1.41 × 10 = 70.3 kg; Devine 50 + 2.3 × 10 = 73.0 kg; Hamwi 106 + 6 × 10 = 166 lb (75.3 kg). His healthy BMI range is roughly 58–77 kg (129–171 lb).
| Formula | Men | Women |
|---|---|---|
| Robinson (1983) | 52 kg + 1.9 kg per inch over 5 ft | 49 kg + 1.7 kg per inch |
| Miller (1983) | 56.2 kg + 1.41 kg per inch | 53.1 kg + 1.36 kg per inch |
| Devine (1974) | 50 kg + 2.3 kg per inch | 45.5 kg + 2.3 kg per inch |
| Hamwi (1964) | 106 lb + 6 lb per inch (≈ 48 kg + 2.7 kg) | 100 lb + 5 lb per inch (≈ 45.4 kg + 2.3 kg) |
Where these formulas come from
Hamwi’s rule of thumb was written for diabetes diet planning and Devine’s 1974 version for drug dosing — still used in hospitals for doses and ventilator volumes. In 1983 Robinson and Miller re-fitted the same straight-line idea to height and weight tables.
None accounts for age, muscle or frame size; Hamwi suggested adding 10% for a large frame and subtracting 10% for a small one. Two people of the same height can both be healthy 10 kg apart, hence the BMI range.
Heights under 5 feet
All four formulas are anchored at 5 ft, with no agreed standard below it. The calculator subtracts the per-inch amount, marks the results as extrapolated and leads with the BMI range; below 4 ft only the BMI range is shown. The BMI calculator or a waist measurement usually tells shorter people more.
Adjusted body weight, predicted body weight and tidal volume
Adjusted body weight = IBW + 0.4 × (actual weight − IBW). It sits between ideal and actual weight because, for some drugs, extra fat holds only part of the extra dose. The 0.4 factor comes from aminoglycoside studies (Bauer and colleagues, 1983); Pai and Paloucek’s review of the IBW equations (Annals of Pharmacotherapy, 2000) traces Devine’s 1974 formula to gentamicin dosing.
Example: a man of 5 ft 10 in weighing 100 kg has an IBW of 73.0 kg (137% of IBW) and an adjusted weight of 83.8 kg. His ARDSNet predicted body weight, 50 + 0.91 × (177.8 − 152.4) = 73.1 kg, gives a tidal volume of 439–585 mL at 6–8 mL/kg (ARDS Network, NEJM 2000). A common convention uses actual weight below IBW, IBW up to 120% of it and adjusted weight above — but drugs differ, so follow your local protocol. These figures are for trained professionals, not self-treatment.
Ideal Weight Calculator FAQ
Which ideal weight formula is most accurate?
None is “correct” for everyone. Devine is the most widely used in medicine, Robinson and Miller fit later population data, and Hamwi is the oldest. Treat the spread between them as a reasonable zone and check it against the healthy BMI range.
Why do the formulas give different answers?
They were built from different data for different purposes — diet planning, drug dosing and insurance tables — so their starting weights and per-inch increments differ.
Is ideal weight the same as healthy weight?
Not quite. The formulas give one number; a healthy weight is a range, and health depends more on body fat, waist size, fitness and blood markers.
How do I convert my height to inches over 5 feet?
Feet × 12 + inches − 60: 5 ft 7 in is 67 inches, 7 over 5 ft. From centimetres, divide by 2.54 first (the height converter helps).
Should athletes use an ideal weight calculator?
With caution: muscular people often weigh more than any formula suggests while being lean. The body fat calculator is a better guide.
What is adjusted body weight?
IBW plus 40% of the weight above it: IBW + 0.4 × (actual − IBW), used for some drug doses and kidney-function estimates in people well above ideal weight.
When should adjusted body weight be used?
Usually when actual weight is more than about 120% of ideal weight, for example for aminoglycosides or the creatinine clearance estimate. Rules vary by drug and hospital, so follow local protocol.
How can I reach my ideal weight safely?
Aim for a gradual change of about 0.5 kg (1 lb) a week. The calorie calculator estimates the daily intake for that rate.