Ideal Weight Calculator
See what four widely used medical formulas say your ideal body weight is for your height and sex, alongside the healthy weight range based on BMI.
Result
- Healthy weight range (BMI 18.5 – 24.9)
- 56.7 kg – 76.3 kg
| Formula | Kilograms | Pounds |
|---|---|---|
| Robinson (1983) | 68.9 kg | 151.9 lb |
| Miller (1983) | 68.7 kg | 151.6 lb |
| Devine (1974) | 70.5 kg | 155.3 lb |
| Hamwi (1964) | 72 kg | 158.8 lb |
What is ideal body weight?
Ideal body weight (IBW) is a height-based estimate of the weight associated with the lowest health risk and, historically, the longest life expectancy. The idea comes from insurance mortality tables of the early 20th century. Today IBW formulas are still used in medicine to dose certain drugs, set ventilator volumes and assess nutrition, and by the public as a simple target. None of the formulas considers body composition, so treat the number as a reference point rather than a goal to hit exactly.
The formulas
Every formula starts from a base weight at 5 feet (152.4 cm) and adds a fixed amount per inch above it:
| 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) | 48 kg + 2.7 kg per inch | 45.5 kg + 2.2 kg per inch |
Worked example: a man who is 175 cm tall is 68.9 inches, or 8.9 inches over 5 feet. Devine gives 50 + 2.3 × 8.9 = 70.5 kg; Robinson gives 52 + 1.9 × 8.9 = 68.9 kg; Miller 56.2 + 1.41 × 8.9 = 68.7 kg; Hamwi 48 + 2.7 × 8.9 = 72.0 kg. The average is about 70 kg, and the healthy BMI range for that height is 56.7 to 76.3 kg.
Healthy BMI range
Because a single number cannot suit every frame, the calculator also shows the weight span that corresponds to a BMI of 18.5 to 24.9. Multiply your height in meters squared by 18.5 and by 24.9 to get the two ends. Most people's ideal-weight formula results sit comfortably inside this range.
How to use this calculator
- Select your units and sex.
- Enter your height. Age is not needed: the formulas apply to adults of all ages.
- Compare the four results and the BMI range. If you want to change your weight, the calorie calculator can set a daily target.
Limitations
The formulas were derived mostly from adult populations of European descent and ignore muscle mass, frame size, ethnicity and age. They are not valid for children or for adults shorter than about 150 cm. This calculator is for information only and is not medical advice.
Frequently asked questions
Why do the formulas give different ideal weights?
Each formula was fitted to a different data set and purpose. Devine and Hamwi were created for calculating drug doses, Robinson and Miller were refined against insurance mortality tables. They agree within a few kilograms for average heights but drift apart for very short or very tall people, which is why the healthy BMI range is a useful complement.
Is my ideal weight the same as my healthy weight?
Not exactly. The formulas give a single number for a typical frame, while the healthy BMI range covers everyone from slim to stocky builds. Being anywhere inside the BMI range of 18.5 to 24.9 is considered healthy for most adults; the formula values usually fall near its middle.
Do these formulas work for people under 5 feet tall?
Not well. All four formulas subtract weight for every inch below 5 feet, and below about 4 feet 10 inches the results become unrealistically low. For shorter adults, rely on the BMI-based healthy range instead.
Should athletes aim for these numbers?
Usually not. The formulas assume average muscle mass, and a strength athlete or rugby player can be well above the "ideal" weight with a low body fat percentage. A body fat measurement is a more meaningful target for athletic people.