BMI Calculator
Calculate your Body Mass Index (BMI) instantly. Enter your height and weight to see your BMI score, weight category and the healthy weight range for your height.
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- 1Enter units in the form on the left.
- 2Fill in the remaining fields — the result updates automatically as you type.
- 3Review the highlighted result and the supporting breakdown on the right.
- 4Use Copy, Share or Print to save or send your result.
What is BMI and how is it calculated?
Body Mass Index is your weight in kilograms divided by your height in meters squared (kg/m²). The World Health Organization classifies adult BMI as: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, and 30+ obese.
BMI is a screening tool, not a diagnosis. It cannot distinguish muscle from fat, so athletes can register 'overweight' while being lean, and older adults can have a 'normal' BMI with low muscle mass. Pair BMI with waist circumference and body-fat measurements for a fuller picture.
Limitations and healthy ranges
BMI categories were derived from population averages, so individual health varies within every category. Some health bodies use adjusted thresholds for certain populations — for example, lower overweight cut-offs for South Asian adults.
Rather than chasing a single number, focus on trends: gradual movement toward the healthy range through diet quality, strength training and daily activity carries most of the proven health benefit.
Frequently Asked Questions
▸What is a healthy BMI?
For most adults a BMI between 18.5 and 24.9 is considered healthy by the WHO. The calculator also shows the weight range corresponding to that BMI for your height.
▸Is BMI accurate for athletes?
Not very — muscle weighs more than fat, so muscular people often have a high BMI despite low body fat. A body fat measurement is more meaningful for athletes.
▸How do I calculate BMI manually?
Divide your weight in kilograms by your height in meters squared. Example: 70 kg ÷ (1.75 m)² = 22.9.