⚖️ Ideal Weight Calculator
By ToolNimba Health Team · Reviewed by ToolNimba Editorial Review, health content · Updated 2026-06-19
This calculator gives a general estimate for healthy adults and is not medical advice. Ideal weight depends on muscle mass, frame size, age and health conditions, and the formulas here do not apply to children, pregnant people or athletes. Talk to a doctor or registered dietitian before setting a weight goal.
The Devine formula gives one reference figure; the BMI range gives a healthy band for your height.
This ideal weight calculator estimates a healthy weight for your height using two trusted methods side by side. Enter your sex and height in metric or imperial units. You will get a single reference figure from the Devine formula (the equation clinicians use for medication dosing) and a healthy weight range based on a BMI of 18.5 to 24.9. Use them together: the Devine number is a midpoint, while the BMI band shows the realistic range of healthy weights for your height.
What is the Ideal Weight Calculator?
There is no single "correct" body weight, which is why the idea of an ideal weight is best treated as a guide rather than a target to hit exactly. Two people of the same height can both be perfectly healthy at quite different weights depending on how much muscle they carry, their frame size and their body composition. The figures here are population averages, not a personal prescription.
The Devine formula was published in 1974 and was originally designed to help calculate drug doses, not to set diet goals. It starts from a base weight at a height of 5 feet (50 kg for men, 45.5 kg for women) and adds 2.3 kg for every inch above that. Because it is built around inches over 5 feet, it works best for adults of roughly average height and tends to drift for people who are very short or very tall. That single number is useful as a quick reference point, but it gives no sense of the range that is still healthy.
That is where the BMI-based range adds value. Body Mass Index divides weight in kilograms by height in metres squared, and a BMI between 18.5 and 24.9 is widely classed as a healthy weight. Rearranging the formula gives a weight band for any height: multiply 18.5 and 24.9 by your height in metres squared. The result is a span of several kilograms rather than one figure, which better reflects the truth that health sits across a range. BMI has real limits (it cannot tell muscle from fat), so use these numbers as a starting point and judge them alongside how you feel, your fitness and advice from a professional.
When to use it
- Getting a realistic, healthy weight range for your height before setting a fitness or diet goal.
- Checking the Devine "ideal body weight" figure that clinicians use as a reference for some medication doses.
- Comparing a single reference weight against the wider healthy band so you do not chase one exact number.
How to use the Ideal Weight Calculator
- Choose metric (cm) or imperial (ft and in) units.
- Select your sex, since the Devine formula uses a different base weight for men and women.
- Enter your height.
- Read the Devine reference weight and the healthy BMI-based weight range, and treat both as guides.
Formula & method
Worked examples
A man who is 5 ft 10 in (70 inches, 1.778 m) tall.
- Inches over 5 ft = 70 − 60 = 10
- Devine = 50 + 2.3 × 10 = 50 + 23 = 73.0 kg
- BMI band = 18.5 × 1.778² to 24.9 × 1.778²
- = 18.5 × 3.161 to 24.9 × 3.161 = 58.5 to 78.7 kg
Result: Devine 73.0 kg; healthy range about 58.5 to 78.7 kg
A woman who is 5 ft 5 in (65 inches, 1.651 m) tall.
- Inches over 5 ft = 65 − 60 = 5
- Devine = 45.5 + 2.3 × 5 = 45.5 + 11.5 = 57.0 kg
- BMI band = 18.5 × 1.651² to 24.9 × 1.651²
- = 18.5 × 2.726 to 24.9 × 2.726 = 50.4 to 67.9 kg
Result: Devine 57.0 kg; healthy range about 50.4 to 67.9 kg
Devine ideal weight and healthy BMI range by height (adults)
| Height | Devine (men) | Devine (women) | Healthy BMI range |
|---|---|---|---|
| 5 ft 0 in (152 cm) | 50.0 kg | 45.5 kg | 42.7 to 57.5 kg |
| 5 ft 4 in (163 cm) | 59.2 kg | 54.7 kg | 49.2 to 66.2 kg |
| 5 ft 8 in (173 cm) | 68.4 kg | 63.9 kg | 55.4 to 74.5 kg |
| 6 ft 0 in (183 cm) | 77.6 kg | 73.1 kg | 62.0 to 83.4 kg |
| 6 ft 4 in (193 cm) | 86.8 kg | 82.3 kg | 68.9 to 92.8 kg |
BMI categories (World Health Organization, adults)
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 to 24.9 | Healthy weight |
| 25.0 to 29.9 | Overweight |
| 30.0 and above | Obesity |
Common mistakes to avoid
- Treating the Devine number as a hard target. The Devine formula gives one reference figure that was designed for medication dosing, not diet goals. Health spans a range, so the BMI band is usually the more realistic guide.
- Applying it to athletes or very muscular people. Muscle is denser than fat, so a fit, muscular person can weigh above an "ideal" figure and still have low body fat. Neither the Devine formula nor BMI separates muscle from fat.
- Using it for children or during pregnancy. These formulas are built for non-pregnant adults. Healthy weight in children is judged against age-and-sex growth charts, and pregnancy weight should be guided by a clinician.
- Mixing height units. Entering centimetres in the imperial fields, or feet in the metric field, produces a wrong result. Pick one unit system and stay in it.
Glossary
- Ideal body weight (IBW)
- A reference weight estimated from height and sex, used as a guide and, in medicine, to help calculate some drug doses.
- Devine formula
- A 1974 equation that estimates ideal body weight from height: a base weight at 5 ft plus 2.3 kg per inch above 5 ft.
- BMI
- Body Mass Index: weight in kilograms divided by height in metres squared. A BMI of 18.5 to 24.9 is classed as a healthy weight.
- Healthy weight range
- The span of weights for your height that fall within a BMI of 18.5 to 24.9, rather than a single number.
Frequently asked questions
What is my ideal weight?
Your ideal weight is best seen as a range, not one number. This calculator shows the Devine-formula reference figure for your height and sex alongside the healthy weight range that matches a BMI of 18.5 to 24.9. A weight anywhere in that band is generally considered healthy.
How is ideal weight calculated?
The Devine formula starts at 50 kg for men or 45.5 kg for women at a height of 5 feet, then adds 2.3 kg for every inch above 5 feet. The healthy range comes from BMI: multiply 18.5 and 24.9 by your height in metres squared.
Is the Devine formula accurate?
It is a useful reference and is still used in clinical dosing, but it was not designed as a personal diet goal. It works best for adults of roughly average height and ignores muscle, frame size and body fat, so pair it with the BMI range and professional advice.
What is a healthy weight for my height?
A healthy weight is one that puts your BMI between 18.5 and 24.9. For example, a person 1.7 m (about 5 ft 7 in) tall has a healthy range of roughly 53 to 72 kg. Enter your height above to see your own band.
Does muscle affect ideal weight?
Yes. Muscle is denser than fat, so muscular people can weigh more than an "ideal" figure while still being lean and healthy. Because neither the Devine formula nor BMI separates muscle from fat, very fit people should read the results with that in mind.
Does this calculator store my data?
No. Everything runs in your browser with JavaScript. Your sex and height are never sent to a server or saved anywhere.
Sources
- Devine BJ, Gentamicin therapy (origin of the ideal body weight formula) , Drug Intelligence & Clinical Pharmacy (1974)
- A healthy lifestyle, WHO recommendations (body mass index) , World Health Organization