Ideal Weight Calculator
A healthy-weight range for your height, using the Devine formula alongside the normal-BMI range — shown in both kilograms and pounds.
What "ideal weight" really means
There is no single perfect number on the scale. What people call an "ideal weight" is really a healthy range, and this calculator shows two useful reference points. The Devine formula gives a classic single-figure estimate based on your height and sex, and we pair it with the full healthy-BMI weight range so you can see the sensible band around that figure.
The Devine formula was originally designed to help calculate medication doses, then became a common shorthand for reference body weight. It begins at 50 kg for men and 45.5 kg for women at five feet of height, then adds 2.3 kg for every additional inch. Because it only uses height, it ignores build and muscle — a lean, muscular person can healthily weigh more than the formula suggests.
How to use the range
Look at the healthy-BMI range first: any weight inside it is generally considered healthy for your height. Use the Devine figure as a midpoint reference rather than a strict goal. Where you aim within the band comes down to your body composition, activity, and health history.
For a more complete view, combine this with our BMI calculator and body fat calculator. Two people at the same weight can have very different amounts of muscle and fat, and that difference matters more than the scale alone.
Devine formula (1974). Healthy weight range derived from WHO/CDC BMI limits of 18.5–24.9.
Frequently asked questions
What is the Devine formula?
The Devine formula estimates a reference body weight from height. It starts at 50 kg for men and 45.5 kg for women at 5 feet tall, adding 2.3 kg for each inch above that. It was created for medication dosing and is now widely used as a rough ideal-weight guide.
Is there really one ideal weight?
No. A healthy weight is a range, not a single figure. That is why this tool shows both the Devine estimate and the full healthy-BMI weight range for your height. Where you sit within that range depends on your build, muscle, and health.
Does the ideal weight differ for men and women?
Yes, slightly. The Devine formula uses a lower starting weight for women, reflecting average differences in body composition. Both sexes share the same healthy-BMI range because BMI categories are not sex-specific.
Should I aim for my "ideal" weight exactly?
Treat it as a reference point, not a mandate. Muscular people may sit above it while being lean and healthy. Use it alongside body-fat percentage and how you feel, and talk to a clinician before setting an aggressive target.