About this ideal weight calculator
Work out the reference body weight for a height using the Devine formula, entered in centimetres or in inches and returned in both kilograms and pounds. Pick male or female, since the formula starts from a different base for each. Before you read the number as a target, know what it is: Devine was published in 1974 to work out drug doses by body size, not to tell anyone what to weigh. It is still widely cited because it is simple and consistent, not because it describes a healthy weight for a particular person. The examples below give common heights so you can see the shape of it.
How the ideal weight calculator works
Devine's formula. For men, 50 kg plus 2.3 kg for every inch of height above five feet; for women, 45.5 kg plus 2.3 kg per inch above five feet. A height in centimetres is converted to inches above the five-foot mark before the multiplier is applied, and an imperial height is taken as total inches — 5'9" is 69. Because the step is per inch, the result moves about 2.3 kg for each inch of height and nothing else changes it. Age, build, muscle and body composition are not inputs, which is both why it is simple and why it should not be read as a personal target.
Ideal Weight Calculator examples
5'0" (152.4 cm)
Male 50 kg / 110.2 lb · Female 45.5 kg / 100.3 lb
5'4" (162.6 cm)
Male 59.2 kg / 130.5 lb · Female 54.7 kg / 120.6 lb
5'9" (175.3 cm)
Male 70.7 kg / 155.9 lb · Female 66.2 kg / 145.9 lb
6'0" (182.9 cm)
Male 77.6 kg / 171.1 lb · Female 73.1 kg / 161.2 lb
Limitations & privacy
Valid for heights from 140 cm to 230 cm, which is roughly 4'7" to 7'7". Devine was designed as a clinical dosing reference. It takes no account of muscle mass, bone density, body frame or age, so a muscular person and a sedentary person of the same height get the same number, and only one of them would find it meaningful. It returns a single figure rather than a range, where a healthy weight is genuinely a range. This is not medical advice and not a goal to aim at. If you want to know what you should weigh, that is a question for a clinician who can see the rest of the picture.
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Ideal Weight Calculator: frequently asked questions
How much should I weigh at 5'9"?
By the Devine formula, 70.7 kg (155.9 lb) for a man and 66.2 kg (145.9 lb) for a woman. Treat that as a reference point rather than a target — the formula knows only your height and sex, so it says nothing about your build, muscle or health.
Can I enter my height in feet and inches?
Yes. Switch Units to Imperial and enter the total inches: 5'9" is 69, 5'4" is 64. Centimetres and inches give the same answer for the same height.
Is this the same as a healthy BMI range?
No. A healthy BMI gives a range of weights for a height; this gives one number, from a different formula built for a different purpose. The two usually land near each other but they are not the same calculation and neither is a verdict on an individual.
Why does the formula differ by sex?
Devine used different starting points — 50 kg for men and 45.5 kg against the same per-inch step — reflecting average body composition differences in the population it was derived from. It is a population average, not a rule about any particular person.
Should I use this number as a personal goal?
No. It was built to size drug doses, not to set weight targets, and it cannot see muscle, frame or age. A sensible target comes from a clinician who can look at more than your height.
Are my measurements stored?
No. The calculation runs in your browser and nothing you enter leaves your device.
Updated October 19, 2026