Health
BMI Calculator
Body Mass Index for adults, with WHO category interpretation.
Inputs
BMI Calculator
Result
BMI
23.5
- Category
- Normal
- Healthy range
- 56.7–76.3 kg
How it's calculated
BMI = weight (kg) / height (m)²
Common questions
Is BMI accurate for athletes?
It doesn't distinguish muscle from fat, so muscular people often score high. Pair with body-fat or waist metrics.
What BMI does and doesn't measure
BMI is a screening ratio of weight to height² — quick, universal, and free. WHO categories: <18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese. It works reasonably well at population scale but doesn't distinguish muscle from fat, so athletes often score high. Pair it with the Body Fat Calculator or waist measurements for a fuller picture.
Using BMI alongside energy needs
If you're targeting a weight change, compute maintenance calories with the TDEE Calculator and baseline metabolic rate with the BMR Calculator, then adjust intake by 300–500 kcal/day for gradual change.
Related calculators
Health
BMR Calculator
Basal Metabolic Rate via Mifflin-St Jeor — calories your body burns at rest.
Health
Body Fat Calculator
US Navy method — body fat percentage from tape measurements.
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Ideal Weight Calculator
Ideal body weight ranges via Devine, Robinson, and Miller formulas.
Health
Calorie (TDEE) Calculator
Total Daily Energy Expenditure — daily calories needed to maintain, lose, or gain weight.