Is being outside this range unhealthy?

Not necessarily. Athletic, muscular individuals commonly fall above this range while being perfectly healthy, and the range itself is a rough estimate rather than a medical threshold.

Why is the range ±10%, not an exact number?

Ideal weight varies by individual factors this formula doesn't capture, so a range gives a more realistic picture than a single precise figure.

Is the Devine formula based on scientific research?

Not directly — a 2000 pharmacy-journal review traced it to an empirical estimate by Dr. Devine's mentor, not a formal population study. It has nonetheless become the standard reference for medication dosing because it works well enough in practice and is simple to apply.

How does this compare to BMI for judging a healthy weight?

They use different logic — BMI compares weight to height² with no formula-based 'ideal' point, while this gives a single reference weight plus a range. Neither accounts for muscle mass, so it's worth checking both alongside a body-fat estimate.

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Health & Fitness

Ideal Weight Calculator

Healthy weight range estimate by height and sex.

🔒 Runs entirely in your browser — nothing here is ever uploaded

About the Ideal Weight Calculator

Estimates a healthy weight range for your height using the Devine formula, a long-standing method originally created for medication dosing that has since become a common general reference for ideal body weight.

How to use it

Select your Sex and Units (metric or imperial — defaults from your region).
Enter your Height.
Optionally enter your Current weight to see where you fall on the gauge.
Read your estimated ideal weight and healthy range in the result panel.

Formula

Men: 50kg + 2.3kg per inch over 5 feet
Women: 45.5kg + 2.3kg per inch over 5 feet
Healthy range = estimate ± 10%

Devised by B.J. Devine (1974) originally for drug-dosing calculations, not derived from a population study — it was an empirical estimate that became the most widely used ideal-body-weight formula in clinical practice. Always computed in kg internally, then converted for display when Imperial units are selected.

Worked example

A 5'9" (175cm) man: 50 + 2.3×9 ≈ 70.7 kg, with a healthy range of roughly 63.6–77.8 kg.

Recommendations

• Frame size, muscle mass, and individual build all affect what's realistic for you — treat this as a reference point, not a strict target.
• Cross-check against BMI and body fat percentage — each method uses different logic and the three rarely agree exactly.
• This formula predates modern body-composition research; it's still widely used as a quick reference, but isn't the most nuanced option available.

Frequently asked questions

The Devine formula was designed as a simple, quick reference and deliberately doesn't account for age, frame size, or muscle mass — that simplicity is also its main limitation.

Related tools

BMI Calculator

Body Fat Calculator

Calorie Calculator

Sources

Pai MP, Paloucek FP — The Origin of the 'Ideal' Body Weight Equations (Annals of Pharmacotherapy, 2000) — accessed 2026-08-19

Disclaimer

Educational estimate, not medical advice. Consult a qualified clinician before making health decisions.