What is an ideal body weight?

Ideal body weight is a weight range associated with reduced risk of weight-related health conditions. It is not a single number. It is a range that depends on height, sex, age, and body composition. The WHO BMI range (18.5–24.9) gives the most evidence-based estimate.

Is this ideal weight calculator completely free?

Yes. No registration, no account, and no payment required.

Do I need an account to use this calculator?

No. Enter your height. All three formula results appear immediately. Nothing is stored.

Why are three formulas shown instead of one?

Different formulas are used in different contexts. Hamwi and Devine are older clinical rules of thumb used in pharmacy and anaesthesia. The WHO BMI range is based on epidemiological data and is the most broadly applicable. Showing all three lets you see the consensus and the spread.

Ideal weight calculator

Ideal weight calculator is a health tool that estimates a healthy weight range from your height and sex. It runs the Hamwi (1964) and Devine (1974) clinical formulas alongside the WHO BMI healthy range (18.5 to 24.9), and supports both metric and imperial units. The tool runs in your browser.

Sex

Height units

Height (cm)

Dedicated pages

Height-specific and demographic ideal weight calculators.

Ideal weight for height calculator

Find your ideal weight range for your height using Hamwi, Devine, and BMI-range formulas. Metric and imperial. Free, in-browser.

Healthy weight calculator

Calculate your healthy weight range based on your height and sex using WHO BMI standards and clinical formulas. Runs in your browser.

Ideal body weight for men

Calculate ideal body weight for men using Hamwi, Devine, and BMI-range formulas. Enter height in metric or imperial. Free, in-browser.

How to find your ideal weight

Select your sex, the Hamwi and Devine formulas differ by sex.
Choose your height unit, centimetres or feet and inches.
Enter your height.
View your ideal weight range from all three formulas side by side, the WHO BMI range is the most evidence-based.

Common uses

Setting a realistic weight loss goal based on your height, then finding the daily calorie target to get there
Understanding where your current weight sits relative to established norms alongside your BMI
Comparing different formula estimates to get a consensus range

Technical specification

Algorithm or formula: Hamwi (1964) men: 48 kg + 2.7 kg per inch over 5 ft; women: 45.5 kg + 2.2 kg per inch over 5 ft. Devine (1974) men: 50 kg + 2.3 kg per inch over 5 ft; women: 45.5 kg + 2.3 kg per inch over 5 ft. WHO range: weight at BMI 18.5 and 24.9 for the given height.
Browser API or library: Pure JavaScript arithmetic. No external library.
Input limits: Height in cm or feet and inches. Sex toggle (Hamwi and Devine only).
Output: Three side-by-side estimates: Hamwi ideal weight, Devine ideal weight, and WHO healthy-weight range.
Known limitations: Hamwi and Devine are clinical rules of thumb originally used for drug dosing, not body-composition assessment. None of the three formulas account for muscle mass or frame size.

Frequently asked questions

What is an ideal body weight?: Ideal body weight is a weight range associated with reduced risk of weight-related health conditions. It is not a single number. It is a range that depends on height, sex, age, and body composition. The WHO BMI range (18.5–24.9) gives the most evidence-based estimate.
Is this ideal weight calculator completely free?: Yes. No registration, no account, and no payment required.
Do I need an account to use this calculator?: No. Enter your height. All three formula results appear immediately. Nothing is stored.
Why are three formulas shown instead of one?: Different formulas are used in different contexts. Hamwi and Devine are older clinical rules of thumb used in pharmacy and anaesthesia. The WHO BMI range is based on epidemiological data and is the most broadly applicable. Showing all three lets you see the consensus and the spread.

Reviewed and tested May 25, 2026.