Ideal weight
Three reference formulas plus the BMI range: a full picture instead of a single number — because ideal weight isn't precise to the gram.
Three formulas, three eras
Broca (19th c.): height − 100 (men) or − 105 (women) — simple but overestimates for tall people. Lorentz (1929) refines it by sex. Devine (1974), created for drug dosing, is still widely used in medicine.
None account for muscle mass, frame or age: treat the average and the BMI range as benchmarks, not goals.
FAQ
Why do the formulas disagree?
Each was calibrated on different populations for different purposes (insurance, medicine, statistics). Their spread is what gives you a realistic range.
Does ideal weight really exist?
Not strictly: your best weight depends on body composition, age and history. The BMI 18.5–25 zone remains the best-documented health benchmark.
Do these work for athletes?
Poorly: muscle mass skews all of them. Body fat percentage is a much better indicator (see our dedicated tool).