Ideal weight calculator
The healthy range is BMI 18.5–24.9 for your height. Devine and Robinson are older formulas made for medicine dosing, shown for comparison; they are not health targets.
A healthy weight for your height is any weight that gives a BMI between 18.5 and 24.9. For someone 165 cm tall that is about 50–68 kg; for 180 cm it is about 60–81 kg. Older formulas such as Devine give a single number, but they were designed for dosing medicine, not as health goals.
How the healthy range is calculated
The range comes straight from the WHO's adult BMI categories. Multiply your height in metres squared by 18.5 for the low end and by 24.9 for the high end. For 1.65 m: 2.7225 × 18.5 ≈ 50.4 kg and 2.7225 × 24.9 ≈ 67.8 kg.
| Height | Healthy range (BMI 18.5–24.9) |
|---|---|
| 155 cm | 44–60 kg |
| 160 cm | 47–64 kg |
| 165 cm | 50–68 kg |
| 170 cm | 53–72 kg |
| 175 cm | 57–76 kg |
| 180 cm | 60–81 kg |
| 185 cm | 63–85 kg |
| 190 cm | 67–90 kg |
The ideal body weight formulas
Formulas like Devine (1974) and Robinson (1983) start from a base weight at 152.4 cm (5 ft) and add a fixed amount for every 2.54 cm (1 inch) above it:
- Devine: men 50 kg + 2.3 kg per inch; women 45.5 kg + 2.3 kg per inch
- Robinson: men 52 kg + 1.9 kg per inch; women 49 kg + 1.7 kg per inch
They are still used in hospitals to estimate drug doses. They ignore age, muscle and frame size, and they were never tested as targets for good health, so treat them as a curiosity rather than a goal.
Choosing your own goal
A good goal is one you can reach and keep. If you are above the range, the first 5–10% of your current weight brings most of the health benefit, and the top of the healthy range is a perfectly good destination. Waist size, energy, strength and blood results matter as much as the number. Our guide on setting a realistic goal weight walks through it step by step, and the calorie calculator shows how much to eat on the way.
These ranges are for adults aged 18 and over who are not pregnant. Some ethnic groups have higher health risk at lower BMIs, and very muscular people may sit above the range while being lean. If you are unsure, ask a doctor or dietitian.
Frequently asked questions
What is my ideal weight for my height?
Any weight that puts your BMI between 18.5 and 24.9. Enter your height above to see that range in kilograms. Within it, the best weight is one you can maintain with healthy habits.
Is the ideal weight different for men and women?
The healthy BMI range is the same. The older Devine and Robinson formulas give men a higher number than women of the same height, which is why the calculator shows them separately.
Should I aim for the middle of the range?
Not necessarily. Health risk is broadly similar across the range. If you are above it, reaching the top of the range is a realistic and worthwhile goal.
Why do different calculators give different ideal weights?
Each formula uses different base numbers and none accounts for muscle or frame size. That is why a BMI-based range is more useful than any single formula result.
Sources
This article is general information, not medical advice. If you have a health condition, are pregnant or under 18, talk to a doctor or registered dietitian before changing your diet.