Discover your healthy weight range using 6 scientific formulas — with frame size adjustment, BMI context, and a full formula comparison.
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Enter your height and sex, then click Calculate Ideal Weight
Ideal body weight (IBW) is an estimate of the optimal weight for a person based on their height and sex. Unlike BMI, IBW formulas give a single target number. They were originally developed for medical use — particularly for calculating drug dosages — but are now widely used in health and fitness.
The Devine formula (1974) is the most used in clinical settings. Robinson (1983) and Miller (1983) are refinements. Hamwi (1964) is common in dietetics. Peterson (2016) is the most modern. The BMI range method uses WHO's 18.5–24.9 healthy BMI band.
People with larger bone structures naturally weigh more at the same height. A large-frame person's ideal weight is typically 10% above the formula result, while a small-frame person's is 10% below. Wrist circumference relative to height is the most practical way to estimate frame size.
IBW formulas don't account for muscle mass, age, ethnicity, or fitness level. Athletes often weigh more than their "ideal" due to muscle — which is perfectly healthy. Use IBW as a general guideline, not a strict target. Always consult a healthcare professional for personalised advice.
Ideal weight varies by sex and formula. For a 175cm male, the range across all formulas is approximately 68–73kg, with a healthy BMI range of 56.5–76.3kg. For a 165cm female, the range is approximately 54–60kg. Enter your details above for a precise calculation.
For general health purposes, the BMI-based range (18.5–24.9) is the most widely accepted. For a single target number, the Devine formula is the most used in clinical medicine. Peterson's formula is the most recently validated. Our calculator shows all six so you can see the consensus range.
Wrap a tape measure around your wrist at the narrowest point. For males over 165cm: small frame is under 17cm, medium is 17–19.9cm, large is 20cm+. For females over 157cm: small is under 15.2cm, medium is 15.2–16.5cm, large is over 16.5cm. Alternatively, encircle your wrist with your thumb and middle finger — if they overlap you are small frame, if they just touch you are medium, if they don't meet you are large.
Yes. At the same height, men typically have a higher ideal weight than women due to greater muscle mass and bone density. For example, at 170cm the Devine formula gives 67.6kg for men and 61.2kg for women — a difference of about 6.4kg. All six formulas in our calculator use sex-specific equations.