BMI Calculator
Enter your height and weight to see your BMI, what category it falls in, and the healthy weight range for your height. Works in kg/cm or lb/ft — nothing is stored or sent anywhere.
How BMI is calculated
BMI (Body Mass Index) is your weight in kilograms divided by your height in metres squared: BMI = kg ÷ m². In imperial units it's weight in pounds times 703, divided by height in inches squared. Someone who is 175 cm and 72 kg has a BMI of 72 ÷ (1.75 × 1.75) ≈ 23.5.
BMI categories
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy range |
| 25 – 29.9 | Overweight |
| 30 and above | Obesity |
What BMI can and can't tell you
BMI is a quick screening number, and at the population level it correlates reasonably well with body fat. At the individual level it has real blind spots: it can't tell muscle from fat, so muscular people score 'overweight' at low body fat, and it says nothing about where fat sits on your body — which matters for health. Treat your BMI as a rough starting point, not a verdict.
For the full picture, read What Is BMI — and What It Can't Tell You.
The number that matters more: your trend
Whatever your BMI today, the useful question is which direction your weight is moving over weeks. A single measurement — BMI included — is a snapshot. A trend is feedback you can act on.
Common questions
- What is a healthy BMI?
- For most adults, a BMI between 18.5 and 24.9 is considered the healthy range. It's a screening range rather than a target — fitness, muscle mass and waist size all shift the picture for individuals.
- How do I calculate BMI manually?
- Divide your weight in kilograms by your height in metres squared. Example: 80 kg ÷ (1.80 m × 1.80 m) = 24.7. In imperial: weight (lb) × 703 ÷ height (in)².
- Is BMI accurate for muscular people?
- No. BMI counts muscle as if it were fat, so athletes and regular lifters often land in the 'overweight' category while lean. Pair BMI with a waist measurement for a more honest read.
- Is this BMI calculator free?
- Yes — free, no sign-up, and nothing you enter is stored or sent anywhere. The calculation runs entirely in your browser.
- What should I do if my BMI is above the healthy range?
- Don't panic over one number. Check it against your waist measurement and how you feel, and if you decide to lose weight, aim for a gradual 0.5–1 kg per week and track your weekly trend rather than daily readings.
This calculator is for general information only and is not medical advice. Talk to a doctor before making significant changes to your diet or exercise, especially if you have a health condition, are pregnant, or are under 18.