A woman of average height
At 165 cm, the four formulas give 56.9, 57.4, 59.8 and 56.4 kg — an average of 57.7 kg.
Ideal weight calculator
This is an estimate for information only. It is not a medical target and does not replace advice from a healthcare professional.
Result
Fill in the fields to see your result.
How it works
Every formula shares the same shape: a base weight for exactly 5 feet, plus a fixed amount for each inch beyond that, with the amount per inch and the base value ranging in different studies. Devine's formula was created for calculating drug dosages and remains the most widely used in that context; the others were later refinements or adjustments from body-composition or actuarial data.
None of them factor in frame size, muscle mass or body composition — two people the same height can have very different genuinely healthy weights, which is exactly why the formulas spread out and none is treated as the single correct answer.
Formulas used
Devine (men / women)
50 kg / 45.5 kg + 2.3 kg per inch above 5 feet
Hamwi (men / women)
48 kg / 45.5 kg + 2.7 kg (men) or 2.2 kg (women) per inch above 5 feet
Worked examples
A man of average height
At 178 cm, the four formulas give 73.2, 71.1, 70.4 and 75.2 kg — an average of 72.5 kg.
Assumptions and limits
- The formulas apply to adults of typical build; they were not developed for children or for people with atypical body composition.
- All four formulas are defined only above 152 cm (5 feet).
Frequently asked questions
Which formula is "right"?
None is definitively correct — they are different statistical estimates from different eras and datasets. Clinicians most often reach for Devine, mainly because it is embedded in standard drug-dosing calculations, not because it is more accurate for describing health.
Why do the results disagree by several kilograms?
Each formula was fit to a different population sample decades apart — the spread between them is a useful reminder that "ideal weight" from height alone is inherently approximate.
Is this the same as a healthy weight?
Not exactly — the healthy-BMI range shown alongside is a different, more commonly used reference today, itself with the same limitation of ignoring body composition.
Should I use this to set a weight-loss target?
Treat it only as a rough reference point. A realistic, healthy target depends on factors these formulas do not see — talk to a healthcare professional for personalized guidance.
Updated
Related calculators
BMI Work out your body mass index, the WHO category it falls in, and the weight range that matches a healthy BMI for your height. Body fat % Estimate body fat percentage from a tape measure using the US Navy method, with the BMI-based method shown for comparison. Calories Estimate how many calories you burn in a day and the daily target for losing, holding or gaining weight. Pregnancy calendar Find your due date and a full week-by-week calendar from your last period, an ultrasound, conception date or IVF transfer. Pregnancy weight gain Find the recommended pregnancy weight gain range by pre-pregnancy BMI, and see how your current gain compares by week. Ovulation calculator Find your fertile window, most likely ovulation day and next period for the current cycle and the six that follow.