"Ideal weight" sounds precise, but it's really a reference point rather than a single perfect number. One of the most established ways to estimate it is the Devine formula, originally created in the 1970s to help with medication dosing. It gives a reasonable target based on your height and sex — here's how it works.
The Devine formula
The formula sets a base weight for the first 5 feet (152.4 cm) of height, then adds a fixed amount per inch above that:
- Men: 50 kg + 2.3 kg for each inch over 5 feet
- Women: 45.5 kg + 2.3 kg for each inch over 5 feet
So height is the only personal input besides sex. Every inch above five feet adds the same 2.3 kg.
A worked example
Take a man who is 5 feet 10 inches tall — that's 10 inches over the 5-foot baseline:
- Base: 50 kg
- Extra: 10 × 2.3 = 23 kg
- Ideal weight: 50 + 23 = 73 kg (about 161 lb)
For a woman of the same height:
- Base: 45.5 kg
- Extra: 10 × 2.3 = 23 kg
- Ideal weight: 45.5 + 23 = 68.5 kg (about 151 lb)
To convert kilograms to pounds, multiply by 2.205.
How to read the result
The Devine number is best treated as the center of a healthy range, not an exact goal. A few things to keep in mind:
- It uses only height and sex, so it ignores muscle mass, frame size, and body composition.
- Very muscular or large-framed people may sit healthily above it.
- It was designed for clinical estimates, not as an aesthetic standard.
Think of it as a sensible anchor. A range of a few kilograms on either side is perfectly normal and healthy for most people.
How to use it
Run your own numbers with the Ideal Weight Calculator. Enter your height and sex, and it returns your Devine estimate in both kilograms and pounds.
For a fuller picture, compare it against the BMI Calculator, which checks your current weight against the standard healthy range. And because the same weight can mean very different body compositions, the Body Fat Calculator helps explain why two people at the same "ideal" weight can look and feel quite different.
The bigger picture
Several formulas exist — Devine, Robinson, Miller, Hamwi — and they produce slightly different numbers, which is a good reminder that none is absolute truth. Your healthiest weight depends on muscle, activity, age, and how you feel day to day, not just a height-based equation.
These figures are general estimates and not medical advice. For goals tailored to your body and health history, talk with a qualified clinician.