Ideal Weight Calculator
Estimate your ideal body weight from height and sex using the clinically cited Devine formula.
Formula last reviewed 4 August 2026 · How we verify our calculators
Ideal body weight
70.5 kg
Updates live as you type
Frequently asked questions
It uses the Devine formula (1974): 50 kg for men or 45.5 kg for women, plus 2.3 kg for every inch of height above 5 feet (152.4 cm).
It was originally created for medication dosing and remains one of the most widely cited ideal-body-weight formulas in clinical settings.
Not exactly. Ideal body weight is a single reference figure; a healthy weight is a range that also depends on body composition, age and frame. Use BMI alongside this.
No. Like most height-based formulas, it ignores muscle mass and frame size, so athletes and larger-framed people may sit healthily above it.
A formula built for drug dosing, not fitness goals
175 cm, male, converts to roughly 68.9 inches — 8.9 inches past the 60-inch (5-foot) baseline this formula starts counting from. Multiply those 8.9 inches by 2.3 kg each (≈20.5 kg) and add the 50 kg male base, and the result is an ideal body weight of about 70.5 kg. The identical height for a woman starts from a 45.5 kg base instead, landing around 66 kg — the only difference between the two calculations is the starting constant; the 2.3 kg-per-inch rate above 5 feet is identical for both.
Where this number actually comes from
This calculator uses the Devine formula, published in 1974 and originally created for a purpose most people don't expect: calculating medication dosages, where clinicians needed a quick, consistent weight estimate rather than a precise health assessment. It's stayed in clinical use for exactly that reason — simplicity and consistency — and become one of the most widely cited "ideal weight" reference figures as a side effect, even though weight-based dosing was the actual design goal.
A single number was never meant to be a verdict
Because it only ever looks at height and sex, the Devine formula has no way to account for muscle mass, frame size or actual body composition — a muscular or larger-framed person can be entirely healthy well above this number, and someone with a smaller frame might sit healthily below it. Treat the figure here as one reference point among several, not a target to hit exactly. Paired with the BMI calculator for a weight-for-height category and the body-fat calculator for an actual composition estimate, these three tools give a rounder picture than any single number can on its own.
This is a general estimate, not medical advice. Consult a doctor or registered dietitian for personalised guidance.
Sources
- Devine BJ (1974) — "Gentamicin therapy," Drug Intelligence & Clinical Pharmacy (origin of the Devine formula, developed for medication dosing)