Ideal Weight Calculator

How to use

1. 1Pick a unit system: Metric (cm) or Imperial (feet + inches), or click a preset to seed a realistic adult height.
2. 2Pick your sex (male or female). Each formula uses a different coefficient for each sex.
3. 3Enter your height. The calculator updates live as you type, with input bounds for safety.
4. 4Read the average of the four formulas in the headline, then check the per-formula breakdown for Devine, Robinson, Miller, and Hamwi with the equation each one used.
5. 5Compare the formula targets to the BMI healthy range (18.5 to 24.9) for the same height, shown in the result panel.
6. 6Use any Copy button to grab a single number, or Copy summary to share the full breakdown.

About this tool

Ideal Weight Calculator computes a target body weight from your sex and height using four classic formulas plus a modern BMI cross-check. Devine 1974 (the original drug-dosing formula), Robinson 1983 (a Devine modification with smaller per-inch increments), Miller 1983 (the most conservative of the four for tall heights), and Hamwi 1964 (the earliest of the four, with the largest per-inch increments) all start from a 5 ft (60 in) baseline and add a fixed amount per inch above that height, with separate male and female coefficients. The calculator runs each formula at your height and sex and shows the result in kilograms or pounds, the per-formula equation it plugged in, and the average of the four numbers as a single headline value. Alongside the four ideal-weight formulas, the result panel reports the BMI healthy weight range (the weight band that produces a BMI between 18.5 and 24.9 for the same height, back-solved as 18.5 times height-in-meters squared up to 24.9 times height-in-meters squared) so you can compare the older formula-based targets to the modern WHO-style range that clinicians use most often today. A unit toggle preserves your inputs when you switch between metric (cm, kg) and imperial (ft+in, lb), preset profiles seed realistic adult heights in one click, and an About these formulas panel lists the value each formula returns at the 60-inch baseline so you can sanity-check the math. Useful for screening a target weight on a weight-loss or maintenance plan, comparing what each formula recommends for a tall or petite frame, picking a target weight before sizing macros or daily calories, or just answering the "what is my ideal weight" question with real equations instead of a generic chart. The four formulas are population-level estimates calibrated for adults near a standard frame size and use only sex and height as inputs, so they can over- or under-estimate for very tall or short heights, athletes with high muscle mass, and older adults with low muscle mass. Below 5 ft (60 in) all four equations extrapolate linearly downward, which is a known limitation. Treat the result as a screening number, not a medical recommendation. The math runs entirely in your browser, so the height and sex you type stay on your device.

Free to use. Works in your browser. No signup, no login.