This ideal body weight calculator shows what four classic medical formulas say your weight “should” be for your height — Devine, Robinson, Miller and Hamwi — plus the healthy BMI weight range for context.
“Ideal” here means statistical/clinical convention, not a verdict on your body — muscular people routinely and healthily exceed every number above. Frame size and composition matter; see the discussion below.
Where These Formulas Came From
Ideal body weight was never really about appearance. The formulas were built for medicine — dosing drugs (aminoglycosides are classically dosed on IBW), setting ventilators and standardizing nutrition. Devine’s 1974 version, a tidy “base weight at 5 feet, plus a fixed amount per extra inch,” became the default and the others are refinements of the same skeleton:
- Devine: men 50 kg + 2.3 kg/inch over 5 ft; women 45.5 + 2.3 (the clinical standard)
- Robinson: gentler slopes (1.9 / 1.7 kg per inch), fitted to broader data
- Miller: the lightest predictions (1.41 / 1.36 kg per inch)
- Hamwi: the 1964 original, steepest for men (2.7 kg/inch)
All four live in our Health Calculators collection, next to the range-based alternative most doctors actually quote today — the BMI healthy band shown in the fifth card.
Worked Example (Verified)
Man, 5′10″ (178 cm) — 10 inches over 5 feet:
- Devine: 50 + 2.3×10 = 73.0 kg (161 lb)
- Robinson: 52 + 1.9×10 = 71.0 kg | Miller: 56.2 + 1.41×10 = 70.3 kg | Hamwi: 48 + 2.7×10 = 75.0 kg
- Healthy BMI band at this height: 58.6–79.2 kg — note how the single-number formulas disagree with each other by 5 kg while the honest range spans 20. Both facts are the lesson.
Reading the Numbers Responsibly
- Frame and muscle break the formulas: a strength athlete at 90 kg and 10% body fat is “20 kg over ideal” by Devine and healthier than most people at 73 kg. Formula IBW assumes an average, untrained composition.
- Below 5 feet the linear formulas extrapolate poorly — the per-inch increments were fitted on average-height adults; short-stature results should be read as rough orientation only.
- Clinicians adjust: actual dosing often uses an “adjusted body weight” blending IBW with actual weight in obesity — the formulas are inputs to judgment, not replacements for it.
- If a number on this page could affect your eating or wellbeing, bring the BMI range and a conversation with your doctor — not a 1974 point estimate — to set goals.
Related Tools
- BMI Calculator — the range view
- Lean Body Mass Calculator — composition over weight
- Health Calculators — the full collection
Frequently Asked Questions
What is the Devine formula for ideal body weight?
Men: 50 kg + 2.3 kg for each inch over 5 feet. Women: 45.5 kg + 2.3 kg per inch over 5 feet. It is the most widely used IBW formula in clinical practice (drug dosing especially).
What is the ideal weight for a 5′10″ man?
The formulas say 70–75 kg (Devine: 73 kg); the healthy BMI range says anywhere from about 59 to 79 kg. Both are conventions — muscle, frame and health markers refine the picture.
Why do the four formulas disagree?
Different decades, datasets and purposes (1964–1983). Their ~5 kg spread at taller heights is a fair picture of the concept’s inherent fuzziness — which is why ranges beat point targets.
Should I try to reach my ideal body weight?
Treat IBW as one reference among several. If you are above the healthy BMI range, moving toward it generally helps health markers; if you are muscular, you may already be healthier above “ideal.” Discuss personal targets with your clinician.
Is ideal body weight used for drug dosing?
Yes — several drug classes (notably aminoglycoside antibiotics and some anesthetics) dose by IBW or an adjusted weight derived from it, because distribution into fat tissue differs from distribution into lean tissue.
Is this ideal body weight calculator free?
Yes — free, instant, no sign-up. Educational only.