Ideal Weight Calculator

How to use it

Enter your height in metric (centimetres) or imperial (feet and inches) and the calculator returns the weight range considered healthy for that height, using the Devine formula — a method originally developed for medical dosing calculations that has since become a standard way to estimate ideal body weight. The Devine formula sets a baseline weight for someone 5 feet (152.4 cm) tall, then adds a fixed amount for every inch above that. For men, the baseline is 50 kg, plus 2.3 kg per inch over 5 feet. For women, the baseline is 45.5 kg, plus 2.3 kg per inch over 5 feet. For example, a man who is 5'10" (70 inches — 10 inches over the 5-foot baseline) has an ideal weight of 50 + (2.3 × 10) = 50 + 23 = 73 kg. A woman of the same height would work out to 45.5 + 23 = 68.5 kg. Rather than a single number, this calculator shows a range — built around a healthy BMI band of 18.5 to 24.9 for that same height — since one exact target weight rarely reflects what's actually healthy for a real body. The Devine formula, like any ideal-weight formula, is a population-level estimate. It doesn't account for muscle mass, bone structure, or frame size, so it can under- or overestimate a healthy weight for people who are more muscular or have a larger or smaller frame than average. It also wasn't designed with children, pregnant women, or older adults in mind. Treat the result as a general reference point, not a target to hit exactly. Two people of the same height and sex can both be healthy at quite different weights depending on muscle, frame, and overall fitness. If you're trying to reach or maintain a particular weight for health reasons, a doctor or registered dietitian can give you guidance that accounts for your full medical picture rather than height alone.

Frequently asked questions

How is the healthy weight range calculated?

It's the weight range that gives a BMI between 18.5 and 24.9 for your height — the range generally considered healthy for adults.

Is a single 'ideal weight' better than a range?

A range is more realistic: healthy weight depends on muscle, frame and other factors. Use the range as a guide, not a strict target.

What formula does this calculator use?

The Devine formula: for men, 50 kg plus 2.3 kg for every inch over 5 feet tall; for women, 45.5 kg plus 2.3 kg per inch over 5 feet. It's a widely used estimate originally developed for medical dosing, not a precise health measurement.

Why does my ideal weight look different from what I expected?

Formula-based estimates don't account for muscle mass, bone density, or frame size, so athletes and people with larger frames often fall outside the calculated range while still being perfectly healthy. Use the range as a general guide alongside other measures, not a strict target.