Ideal Weight Calculator

What it measures

This calculator estimates the weight range associated with good health for your height and sex, using the healthy-BMI range (18.5–24.9 × height²) as the primary output, and four widely-cited clinical formulas — Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964) — as secondary point estimates. It is an educational screening aid, not a clinical prescription.

How it works

You enter your sex and height (metric or imperial). The calculator derives the healthy weight range from the WHO BMI bounds (18.5–24.9 kg/m²) multiplied by your height in metres squared. Each of the four historical formulas then adds a fixed per-inch increment above 5 ft (152.4 cm) to a sex-specific base weight. Results are shown in your chosen unit system.

Tips for an accurate result

• 1Focus on the range, not a single number — A 10–15 kg window is normal for most heights. Aiming for the lower or upper end of the healthy-BMI range rather than a specific formula value is generally better supported by evidence.
• 2Add waist circumference for fuller context — Waist measurement above 88 cm (35 in) for women or 102 cm (40 in) for men indicates higher metabolic risk regardless of ideal-weight estimates. Use it alongside this calculator.
• 3Gradual change is more sustainable — Even a 5–10 % reduction in body weight can lower blood pressure, improve blood glucose, and reduce cardiovascular risk — without needing to reach any particular formula target.
• 4Physical fitness matters independently — A moderately active person slightly above the healthy-BMI range may have lower cardiovascular risk than a sedentary person within it. Weight and fitness are separate health levers.
• 5Speak to your GP before making large changes — If you are significantly outside the healthy range, or have an existing health condition, professional guidance before any major dietary or exercise programme is strongly advisable.