How to use it
- Choose your sex.
- Enter your height in feet and inches or in centimeters.
- Optionally enter your current weight.
- Compare the healthy range and the four formula results.
Healthy weight range
The headline result is the weight range that gives a BMI of 18.5 to 24.9 at your height, the "normal weight" range used by the CDC, NIH and WHO. For a 5 ft 6 in adult, that's about 115 to 154 lb. If you enter your current weight, the calculator shows your BMI and how far you are above or below the range.
The four ideal weight formulas
All four formulas start with a base weight at 5 feet and add a fixed amount for each inch above it:
| Formula | Men | Women |
|---|---|---|
| Devine (1974) | 50 kg + 2.3 kg per inch | 45.5 kg + 2.3 kg per inch |
| Robinson (1983) | 52 kg + 1.9 kg per inch | 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 |
| Hamwi (1964) | 106 lb + 6 lb per inch | 100 lb + 5 lb per inch |
The Devine formula was originally created to calculate drug doses and is still the most widely used in hospitals. The calculator shows each result, the range between the lowest and highest, and their average.
Worked example
A woman who is 5 ft 6 in (6 inches over 5 feet):
- Devine: 45.5 + 2.3 × 6 = 59.3 kg ≈ 131 lb
- Robinson: 49 + 1.7 × 6 = 59.2 kg ≈ 131 lb
- Miller: 53.1 + 1.36 × 6 = 61.3 kg ≈ 135 lb
- Hamwi: 100 + 5 × 6 = 130 lb
All four land comfortably inside her healthy BMI range of about 115 to 154 lb.
Why one number isn't the whole story
These formulas give one number, but a healthy weight is really a range that depends on muscle mass, frame size, age and where you carry fat. Two people of the same height can both be healthy at weights 20 lb apart. Athletes and people with lots of muscle often weigh more than the formulas suggest while being lean.
The formulas were designed for adults taller than 5 feet; below that, the calculator warns you and you should rely on the BMI range. They don't apply to children, during pregnancy or to athletes. For a sense of body composition, try the body fat calculator or the waist-to-hip ratio calculator.
Using your result
If you're above the range, even a 5–10% weight loss can improve blood pressure, blood sugar and cholesterol. The calorie deficit calculator helps you set a realistic daily target. If you're below the range, talk to your doctor, especially if you've lost weight without trying.
This calculator is informational and isn't medical advice. All calculations run in your browser.
Frequently asked questions
What is my ideal weight for my height?
A healthy range for adults is the weight that gives a BMI of 18.5–24.9. For 5 ft 6 in, that's about 115–154 lb. The formulas give single values within or near that range.
Which ideal weight formula is the most accurate?
None is clearly best. Devine is the most widely used clinically; Robinson and Miller give slightly different values. Use the range rather than one number.
Is ideal weight different for men and women?
Yes. All four formulas use a lower base weight for women.
Does age change my ideal weight?
The formulas don't include age. Some research suggests slightly higher BMIs may be fine in older adults, so talk to your doctor.
Can I use this if I'm shorter than 5 feet?
The formulas aren't reliable below 5 feet. Use the healthy BMI range instead.
Sources
- NHLBI: Calculate your body mass index
- Peterson CM et al.: Universal equation for estimating ideal body weight and body weight at any BMI (Am J Clin Nutr, 2016)
- Pai MP, Paloucek FP: The origin of the "ideal" body weight equations. Ann Pharmacother 2000 (PubMed)
Last reviewed: November 14, 2026 · Kitpebble editorial team
Change log
- : Sources expanded; FAQ and content reviewed.
- : Sources expanded; FAQ and content reviewed.
For general information only; not medical advice or a diagnosis. How we write and review our pages