Ideal Weight Calculator
See the ideal weight for your height by three published formulas, with the healthy range beside them.
Ideal Weight Calculator
Ideal weight
67.75
- Healthy range for your height54.7 to 73.7 kg
- Against your weight now12.3 kg above the average of the three
- Robinson formula66.66
- Devine formula67.75
- Hamwi formula68.83
Works out in your browser. Nothing you type is sent anywhere.
In short: Ideal Weight Calculator
For the height entered, the three formulas average 67.75 kilograms: 66.66 by Robinson, 67.75 by Devine and 68.83 by Hamwi. A healthy BMI for that height spans 54.7 to 73.7 kg, which is a wider and more useful target. Your weight is 12.3 kg above the average of the three.
What is Ideal Weight?
Ideal body weight is a reference figure for a given height, originally devised for medical dosing rather than as a target to aim at.
How is Ideal Weight calculated?
Each formula starts from a base weight at five feet and adds a fixed amount for every inch above that, with different numbers for men and women. The three differ only in those constants, which is why they disagree by a few kilograms.
- Wthe ideal weight in kilograms
- basethe formula's weight at five feet
- kthe weight added for each inch above five feet
- h_inchesheight in inches
A worked example
| Sex | Male |
|---|---|
| Height (cm) | 172 |
| Your weight now (kg) | 80 |
| Result | |
| Ideal weight | 67.75 |
| Healthy range for your height | 54.7 to 73.7 kg |
| Against your weight now | 12.3 kg above the average of the three |
| Robinson formula | 66.66 |
| Devine formula | 67.75 |
| Hamwi formula | 68.83 |
Every figure in this table is produced by the same calculation the tool above runs.
How to use this ideal weight calculator
- Enter your sex and your height in centimetres.
- Enter your current weight to see the difference.
- Read the three formulas, and note that they disagree.
- Compare them with the healthy BMI range, which is a range rather than a point.
Questions people ask
Why do the three formulas disagree?
Because each was derived from a different population at a different time, and all three are simple straight lines fitted to averages. The differences between them are a fair signal of how imprecise the whole idea is. That is why the average and the range are shown together.
Should I aim for the ideal weight figure?
Not as a precise target. These formulas were built for medical dosing, not for setting personal goals, and they ignore build and muscle entirely. The healthy BMI range is a better guide, and a doctor who can see you is better still.
Do they work for very tall or very short people?
Less well, because a straight line fitted around average heights drifts at the extremes. Someone well outside the usual range should treat the figures with caution. The BMI range handles height more sensibly.
Why are the formulas based on inches?
Because they were published in countries using imperial units, and each adds a fixed weight per inch over five feet. The tool converts your height in centimetres before applying them. The output is in kilograms.
Accuracy and sources
For general information. Not medical advice.
Checked by the Daytoolz team on 16 October 2026. How we check our tools.
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