CALCULATOR
BMI Calculator
Your BMI, your category, and the healthy weight range for your height in kg and cm. Then the part BMI cannot tell you: what to actually eat.
BMI is a population screening tool, not a diagnosis. It cannot tell muscle from fat.
What BMI does and does not tell you
BMI is your weight in kilograms divided by your height in metres squared. It was designed in the 19th century to describe populations, not individuals, and it remains a useful screening signal precisely because it is so simple to calculate.
Its central limitation is that it cannot distinguish muscle from fat. A trained lifter and a sedentary person of the same height and weight get the same BMI and are in completely different health situations. It also ignores where fat is stored, which matters more for metabolic risk than the total.
Use BMI as one rough signal. If you want a number that reflects your actual composition, measure body fat percentage instead, and if you want a number you can act on, calculate calorie and protein targets.
The BMI formula
Example: 80 kg at 1.75 m
BMI = 80 / (1.75 x 1.75) = 26.1
BMI categories for adults
| Category | BMI range | Notes |
|---|---|---|
| Underweight | Below 18.5 | May indicate under-nutrition or illness |
| Healthy range | 18.5 - 24.9 | Population reference range |
| Overweight | 25.0 - 29.9 | Common for muscular people too |
| Obese class I | 30.0 - 34.9 | Raised metabolic risk |
| Obese class II | 35.0 - 39.9 | High metabolic risk |
| Obese class III | 40.0 and above | Very high metabolic risk |
Healthy weight range by height
| Height | Healthy weight (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 |
Where BMI misleads
- Muscle reads as fat. Muscle is denser, so trained people frequently land in the overweight category while carrying low body fat.
- It ignores fat distribution. Visceral fat around the organs carries more metabolic risk than the same mass on hips and thighs, and BMI cannot see the difference.
- It was built on limited populations. The thresholds derive largely from European data, and some health bodies use lower cut-offs for South Asian populations.
- It says nothing about direction. A stable BMI of 27 in someone training and eating well is a different situation from a BMI of 27 climbing quickly.
A waist measurement adds most of what BMI misses, and body fat percentage adds the rest. If your BMI reads high and you lift regularly, check body fat before drawing any conclusion.
Frequently asked questions
What is a healthy BMI?
Is BMI accurate for athletes?
How do I calculate BMI manually?
What should I use instead of BMI?
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General information, not medical advice. Consult a qualified professional before changing your diet, especially with a medical condition.