An ideal weight calculator estimates a reference body weight for your height and sex, here with the Devine formula used in medicine. For a man 170 cm tall the Devine ideal body weight is 65.9 kg, and for a woman of the same height 61.4 kg.
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How to use the ideal weight calculator
- Choose male or female.
- Enter your height in centimetres.
- Read your ideal body weight in kilograms.
- Compare it with the healthy BMI range for your height in the table above.
Ideal weight calculator formula (Devine)
- Height in inches = height in cm ÷ 2.54
- Men: ideal body weight = 50 kg + 2.3 kg for each inch over 5 feet (60 inches)
- Women: ideal body weight = 45.5 kg + 2.3 kg for each inch over 5 feet
- Below 5 feet the tool returns the base weight (50 or 45.5 kg)
The Devine formula was published in 1974 to help dose medicines, and it is still widely used in hospitals for that purpose.
Ideal weight calculator worked example
| Height | Men (Devine) | Women (Devine) | Healthy BMI range (18.5 to under 25) |
|---|---|---|---|
| 155 cm | 52.4 kg | 47.9 kg | 44.4–60.1 kg |
| 160 cm | 56.9 kg | 52.4 kg | 47.4–64.0 kg |
| 165 cm | 61.4 kg | 56.9 kg | 50.4–68.1 kg |
| 170 cm | 65.9 kg | 61.4 kg | 53.5–72.2 kg |
| 175 cm | 70.5 kg | 66.0 kg | 56.7–76.6 kg |
| 180 cm | 75.0 kg | 70.5 kg | 59.9–81.0 kg |
| 185 cm | 79.5 kg | 75.0 kg | 63.3–85.6 kg |
For a man 170 cm tall: 170 ÷ 2.54 = 66.9 inches, 6.9 inches over 5 feet, so 50 + 2.3 × 6.9 = 65.9 kg.
Other ideal body weight formulas
| Formula (year) | Men | Women | At 170 cm (men / women) |
|---|---|---|---|
| Devine (1974) | 50 + 2.3 kg/in | 45.5 + 2.3 kg/in | 65.9 / 61.4 kg |
| Robinson (1983) | 52 + 1.9 kg/in | 49 + 1.7 kg/in | 65.2 / 60.8 kg |
| Miller (1983) | 56.2 + 1.41 kg/in | 53.1 + 1.36 kg/in | 66.0 / 62.5 kg |
| Hamwi (1964) | 48 + 2.7 kg/in | 45.5 + 2.2 kg/in | 66.7 / 60.7 kg |
Each formula counts inches over 5 feet. They give different answers because they were fitted to different data, which is a reminder that “ideal” weight is an estimate, not a target you must hit. Talk to a doctor before setting a weight goal.
Ideal weight vs a healthy BMI range
The CDC classes a BMI of 18.5 to less than 25 as healthy weight for adults 20 and older. That gives a range rather than a single number: at 170 cm it is about 53.5 to just under 72.3 kg. BMI and ideal body weight formulas do not account for muscle, bone structure, age or ethnicity, so an athlete may be above both and still be healthy.
When the ideal weight calculator is useful
- As a rough reference point alongside a BMI range and waist measurement.
- To understand dosing or ventilator settings a clinician may base on ideal body weight.
- Not for children or teenagers, for whom growth charts are used instead.
For general information only, not medical advice. Your midwife, doctor or other clinician should confirm dates and care decisions.
Using the number sensibly
The ideal weight calculator gives one figure for each height and sex, but healthy weights cover a range. Use the result as one reference point, alongside your BMI, waist measurement and how you feel, rather than as a goal you must reach. A person with a lot of muscle can be well above the Devine figure and still be healthy, and an older adult may be healthier slightly above it than below it.
If you want to change your weight, slow and steady changes in eating and activity are easier to keep up. The CDC notes that people who lose weight gradually, about 1 to 2 pounds a week, are more likely to keep it off. The federal Physical Activity Guidelines recommend at least 150 minutes a week of moderate-intensity activity for adults, plus muscle-strengthening activity on two or more days.
How clinicians use ideal body weight
In hospitals, ideal body weight is used less as a target and more as an input. Some medicine doses and ventilator settings are based on ideal body weight rather than actual weight, because lean tissue drives how the body handles them. That is why formulas such as Devine remain in use even though they were never intended to define a healthy weight. If an ideal weight calculator result is used for your care, your clinician will explain why.
Related converters and calculators
Related calculators:
- BMI calculator: BMI
- Healthy weight calculator: range
- Body fat calculator: body fat
- Lean body mass calculator: lean mass
Sources
CDC: Adult BMI categories; NIH NHLBI: Calculate your BMI; CDC: Growth charts.
Questions about this calculator
What is the Devine formula?
50 kg for men or 45.5 kg for women, plus 2.3 kg for each inch over 5 feet.
What is my ideal weight at 170 cm?
About 65.9 kg for a man and 61.4 kg for a woman by Devine.
Which ideal weight formula is best?
None is best for everyone; they are estimates fitted to different data.
Is ideal weight the same as a healthy BMI?
No. A healthy BMI of 18.5 to under 25 gives a range rather than one number.
Can children use this?
No. Children and teens are assessed with growth charts.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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