Ideal Weight Calculator
Find your ideal body weight using four classic medical formulas: Robinson, Miller, Devine, and Hamwi.
What is Ideal Weight Calculator?
The ideal weight calculator estimates a healthy weight range for your height using four classic medical formulas still used in clinical practice and drug dosing, plus the World Health Organization's healthy BMI range (18.5–24.9).
There is no single correct "ideal" weight — these formulas predate modern body-composition tools and do not adjust for muscle mass or frame size. Use the range as a reasonable target, not a rigid goal.
Formula
Each formula starts with a base weight at 5'0" (60 in) and adds a per-inch adjustment for each inch above that:
- Robinson (men): 52 kg + 1.9 kg/in; (women): 49 + 1.7 kg/in
- Miller (men): 56.2 + 1.41; (women): 53.1 + 1.36
- Devine (men): 50 + 2.3; (women): 45.5 + 2.3 — most common in drug dosing
- Hamwi (men): 48 + 2.7; (women): 45.5 + 2.2
Healthy BMI range uses weight = BMI × height² (m).
Worked example
A man 5'9" (69 in, 9 inches over 60):
- Robinson = 52 + 1.9×9 = 69.1 kg (152.4 lb)
- Miller = 56.2 + 1.41×9 = 68.9 kg (151.9 lb)
- Devine = 50 + 2.3×9 = 70.7 kg (155.9 lb)
- Hamwi = 48 + 2.7×9 = 72.3 kg (159.4 lb)
- Healthy BMI range: 125–169 lb
How to use this calculator
- Pick your sex and unit system.
- Enter your height.
- Compare the four formulas and the WHO healthy BMI range — your target should be in that general neighborhood if your body composition is average.
Frequently asked questions
Which formula should I use?
Clinicians most often use the Devine formula for drug dosing. For a general health target, any formula within 3–5 lb is a reasonable benchmark. The healthy BMI range is a good sanity check.
These formulas say I am "overweight" but I lift weights. Am I?
No. All four formulas and BMI fail for muscular athletes. A lean 190-lb man at 5'9" with 12% body fat is healthier than a 155-lb man at 5'9" with 28% body fat. Use the body-fat calculator instead if you train seriously.
Are ideal weights different for older adults?
Yes. Research suggests older adults (65+) may benefit from slightly higher body weight (BMI 22–27) as a reserve against illness. Formulas here do not adjust for age.
What about people under 5 feet tall?
The formulas return the base weight (no adjustment) at or below 60 in. For children and short-statured adults, growth charts or clinical assessment are more appropriate than these formulas.