About the Ideal Weight Calculator
Ideal body weight is a reference figure — a single estimate of what a person's weight would be, based purely on height and sex, without factoring in their actual current weight, muscle mass, or frame size. It's a starting point for comparison, not a target to force yourself toward.
This calculator uses the Devine formula, originally developed in 1974 to help clinicians estimate a patient's weight for calculating accurate drug dosages (like the antibiotic gentamicin, where dosing by actual body weight can be misleading in people who carry a lot of extra fat or fluid). It has since become the most widely referenced reference-weight formula in clinical practice — more commonly cited than alternatives like the Robinson, Miller, or Hamwi formulas. It sets a base weight at 5 feet tall (50 kg for men, 45.5 kg for women) and adds 2.3 kg for every inch above that.
Because the formula only uses height and sex, it doesn't know anything about your actual body composition — a muscular, athletic person will often weigh noticeably more than their "ideal weight" here while being perfectly healthy. For a fuller picture, use this alongside BMI or Body Fat Calculator rather than treating this number in isolation.
Devine, B.J. (1974). 'Gentamicin therapy.' Drug Intelligence & Clinical Pharmacy, 8, 650–655.