This ideal weight calculator answers the question "how much should I weigh?" using four widely cited medical formulas — Devine, Robinson, Miller, and Hamwi — plus the healthy weight range defined by a BMI of 18.5 to 25. Because each formula weighs height slightly differently, the calculator combines them into a single consensus range rather than one misleading number.
Enter your gender and height in feet and inches or centimeters, then press Calculate. You will see each formula’s estimate side by side, the consensus range, and the BMI-based healthy range, so you can judge where your current weight falls relative to established medical benchmarks.
How Ideal Body Weight Formulas Work
All four formulas share the same structure: a base weight for a 5-foot person, plus a fixed number of kilograms for every inch of height above 5 feet.
- Devine (1974): men 50 kg + 2.3 kg/inch; women 45.5 kg + 2.3 kg/inch
- Robinson (1983): men 52 kg + 1.9 kg/inch; women 49 kg + 1.7 kg/inch
- Miller (1983): men 56.2 kg + 1.41 kg/inch; women 53.1 kg + 1.36 kg/inch
- Hamwi (1964): men 48 kg + 2.7 kg/inch; women 45.5 kg + 2.2 kg/inch
The Devine formula was originally created for calculating drug dosages, and it remains the standard for medication dosing in hospitals today. The others were later refinements based on population height-weight data. None of them measure body fat directly, which is why the calculator also shows the BMI-based range.
Which Number Should You Aim For?
Treat the consensus range as a reference point, not a target etched in stone. A few practical rules of thumb:
- If you strength train regularly, expect to sit above the formula estimates — muscle is denser than fat, and these formulas were built from general population data.
- Frame size matters: wrist circumference over 7.5 inches (men) or 6.5 inches (women) generally indicates a larger frame, which can add roughly 10% to the estimate.
- The BMI range of 18.5–25 is the range associated with the lowest all-cause mortality in large studies, so anywhere inside it is medically reasonable.
- Waist circumference (under 40 in for men, 35 in for women) is a better health screen than scale weight alone.
Example: 5′10″ Male
Consider a 5-foot-10-inch man — that is 10 inches over 5 feet.
- Devine: 50 + 2.3 × 10 = 73.0 kg (161 lbs)
- Robinson: 52 + 1.9 × 10 = 71.0 kg (157 lbs)
- Miller: 56.2 + 1.41 × 10 = 70.3 kg (155 lbs)
- Hamwi: 48 + 2.7 × 10 = 75.0 kg (165 lbs)
The consensus range is roughly 70–75 kg (155–165 lbs). For comparison, the healthy BMI range for 5′10″ spans 58.5–79.0 kg (129–174 lbs), so the formulas cluster in the upper-middle portion of the medically healthy zone.
Frequently Asked Questions
How much should I weigh for my height?
For most adults, a healthy weight keeps BMI between 18.5 and 25. For a 5′6″ person that is roughly 115–155 lbs; for 5′10″ it is roughly 129–174 lbs. The Devine, Robinson, Miller, and Hamwi formulas narrow this to a tighter consensus range based on gender and height.
Which ideal weight formula is most accurate?
No single formula is definitively best. The Devine formula is the clinical standard because hospitals use it for drug dosing, while Robinson and Miller were later statistical refinements. Because they differ by only a few kilograms, the most honest answer is the consensus range spanning all four.
Do these formulas work for very short or very tall people?
They are least reliable outside roughly 5 ft to 6 ft 4 in, since they were derived from average-height populations. For heights under 5 feet, this calculator uses the base weight, and the BMI-based range becomes the more trustworthy benchmark at any extreme height.
Why is my ideal weight different for men and women?
Men carry more muscle and bone mass on average at the same height, so every formula assigns men a higher base weight — for example, Devine uses 50 kg for men versus 45.5 kg for women at 5 feet. Women naturally carry more essential body fat, which weighs less per unit volume than muscle.
Is BMI or ideal body weight a better health measure?
Neither measures body composition. BMI defines a broad healthy range (18.5–25), while ideal weight formulas give a narrower point estimate inside it. For actual health assessment, waist circumference and body fat percentage are more informative — use this calculator as a screening reference, not a diagnosis.