“What should I weigh?” has no single right answer, but several well-known formulas can give you a reasonable range to start from.
Popular ideal weight formulas
All three use height over 5 feet (60 inches).
Devine formula
- Men: 50 kg + 2.3 kg per inch over 5 feet
- Women: 45.5 kg + 2.3 kg per inch over 5 feet
Robinson formula
- Men: 52 kg + 1.9 kg per inch over 5 feet
- Women: 49 kg + 1.7 kg per inch over 5 feet
Hamwi formula
- Men: 106 lb + 6 lb per inch over 5 feet
- Women: 100 lb + 5 lb per inch over 5 feet
Worked examples
A man who is 5 ft 10 in (10 inches over 5 feet):
- Devine: 50 + 23 = 73 kg
- Robinson: 52 + 19 = 71 kg
- Hamwi: 106 + 60 = 166 lb, or about 75 kg
A woman who is 5 ft 6 in (6 inches over 5 feet):
- Devine: 45.5 + 13.8 = about 59 kg
- Robinson: 49 + 10.2 = about 59 kg
- Hamwi: 100 + 30 = 130 lb, or about 59 kg
Notice that the formulas land close together, but not on the same number. That is a clue that you should think in ranges.
The healthy BMI range gives a wider picture
A BMI of 18.5 to 24.9 is considered the healthy range for most adults. For someone 1.78 m tall, that works out to roughly 59 kg to 79 kg. That is a 20 kg window, which is much more realistic than a single “ideal” number.
Limits of these formulas
- They do not account for muscle mass, bone structure, or age.
- They were designed for general reference, not individual medical targets.
- Your best weight is also the one where you have good energy, healthy lab results, and sustainable habits.
Try the calculators
Enter your height and sex into an ideal weight calculator to see results from several formulas side by side. You can also check your healthy weight range based on BMI, or calculate your BMI directly.
Tips for choosing a goal
- Aim for a range, not an exact number.
- Focus on habits such as sleep, movement, and balanced meals.
- Track waist measurement or body fat along with weight.
- Talk to a healthcare professional before setting a major weight goal.
This article is for general information only and is not medical advice. If you have concerns about your weight or eating, please speak with a doctor.
