Ideal Weight & Body Fat Calculator
Find your ideal weight for your height and sex with four well-known formulas and your healthy weight range. Add a few tape measurements to estimate your body fat percentage too.
Ideal weight by formula
How to use the ideal weight calculator
- Choose Ideal weight or Body fat at the top. Switch to US units if you use pounds and inches.
- Select your sex and enter your height. Your ideal weight, healthy weight range and all four formula results appear instantly.
- Add your current weight to see where you are on the scale and how far you are from the healthy range.
- For body fat, enter your age, weight and tape measurements of your neck and waist (plus hip for women). How to measure explains where to place the tape.
- The side tables show ideal weight for other heights and the body fat categories.
How is ideal weight calculated?
“Ideal weight” is not a single number but a range that is considered healthy for your height. This tool shows two approaches side by side: the World Health Organization’s healthy body mass index (BMI) range of 18.5–24.9, and four classic ideal body weight formulas that were created in medicine for drug dosing. The main result is the average of the four formulas.
The four ideal weight formulas
All of them work the same way: they start from a base weight for a height of 5 ft (152.4 cm) and add a fixed amount for every inch (2.54 cm) above it.
| Formula | Women | Men |
|---|---|---|
| Devine (1974) | 45.5 kg + 2.3 kg | 50 kg + 2.3 kg |
| Robinson (1983) | 49 kg + 1.7 kg | 52 kg + 1.9 kg |
| Miller (1983) | 53.1 kg + 1.36 kg | 56.2 kg + 1.41 kg |
| Hamwi (1964) | 45.5 kg + 2.2 kg | 48 kg + 2.7 kg |
For a 6 ft (183 cm) man, the formulas give about 73.1–80.4 kg (161–177 lb); a 5 ft 5 in (165 cm) woman gets about 56.4–59.8 kg (124–132 lb), with a healthy BMI range of 50.4–67.8 kg. Try it in the calculator.
Healthy BMI range
Healthy weight = 18.5 × height² … 24.9 × height² (height in meters)
The formulas ignore muscle and frame size, so for broad-shouldered or muscular people a realistic weight is usually above the formula result but still inside the BMI range. Below 5 ft (152 cm) the formulas become unreliable; go by the BMI range instead.
How is body fat percentage calculated?
Two people with the same weight can look very different: one may carry more muscle, the other more fat. Body fat percentage shows that difference. This tool uses the tape method of the U.S. Navy. Men need height, neck and waist; women also measure the hip:
Men: 495 ÷ (1.0324 − 0.19077 × log(waist − neck) + 0.15456 × log(height)) − 450
Women: 495 ÷ (1.29579 − 0.35004 × log(waist + hip − neck) + 0.22100 × log(height)) − 450
Measurements are in centimeters. A 35-year-old man who is 178 cm tall, weighs 82 kg and has a 38 cm neck and a 90 cm waist has about 20.2% body fat, in the “Average” category. Open this example. For comparison, the tool also shows a second estimate based on age and BMI (the Deurenberg formula).
Measured carefully, the tape method is usually within 3–4 percentage points. To track change, measure at the same time of day and at the same spots. If you are pregnant, have a chronic condition or are under 18, ask a doctor. Everything is calculated in your browser and nothing you enter is sent to a server.
Frequently asked questions
What should I weigh for my height?
There is no single right number. The healthy BMI range (18.5–24.9) gives a wide range for your height, for example 53.5–72.0 kg (118–159 lb) at 170 cm (5 ft 7 in). The ideal weight formulas suggest a value near the middle: about 61 kg (135 lb) for women and 66 kg (145 lb) for men at that height.
Why do the ideal weight formulas give different results?
The Devine, Robinson, Miller and Hamwi formulas were developed in different years from different groups of people. All of them are rough estimates and usually differ by only a few kilograms. That is why this tool shows the average of all four next to the healthy BMI range.
What is a healthy body fat percentage?
According to the ACE chart, 21–24% is fitness level and 25–31% average for women; for men it is 14–17% and 18–24%. 32% and above for women and 25% and above for men is classed as obese. Essential fat, the minimum needed to live, is 10–13% for women and 2–5% for men.
How accurate is the tape measure method?
Measured carefully, the U.S. Navy method is within about 3–4 percentage points for most people. The error can be larger for very muscular people or those who carry fat mainly around the belly. Clinical methods like DEXA are more precise, but a tape is enough to track change over time.
Is the data I enter saved?
No. The calculation runs entirely in your browser and nothing is sent anywhere. For convenience, your last values are remembered on your own device only; you can remove them with the Clear button.