BMI Calculator
Calculate BMI from metric or imperial height and weight, see the WHO category, and the healthy weight range for your height.
Processed locally in your browser — nothing is uploaded.
BMI Calculator
Enter your height and weight to see your BMI.
About BMI Calculator
Body mass index is weight divided by height squared (kg/m²) — a quick screening number the WHO buckets into underweight, healthy, overweight, and obesity classes. Enter your height and weight in either metric or imperial units and the calculator shows your BMI, its category, and the weight range that would put you in the 18.5–24.9 band for your height.
Common uses
- Get a quick read on where your weight falls for your height
- See the healthy weight range to frame a realistic goal
- Convert a doctor's metric BMI conversation into pounds and inches
Example
Input
70 kg at 1.75 m
Output
BMI 22.9 — Healthy weight (range 56.7–76.3 kg)
Limitations
- BMI can't distinguish muscle from fat, so athletes often read 'overweight' while lean.
- Adult cut-offs don't apply to children, during pregnancy, or uniformly across ages and ethnicities — it's a screening number, not a diagnosis.
Frequently asked questions
How is BMI calculated?
BMI is your weight in kilograms divided by your height in meters squared: kg ÷ m². Someone 1.75 m tall weighing 70 kg has a BMI of 70 ÷ (1.75 × 1.75) = 22.9.
Is my height and weight uploaded anywhere?
No. The calculation runs entirely in your browser and the values you enter are never transmitted or stored, so this body data stays on your device.
What BMI is considered healthy?
For adults, the WHO healthy range is a BMI of 18.5 to 24.9. Below 18.5 is underweight, 25–29.9 is overweight, and 30 and above is split into obesity classes I (30–34.9), II (35–39.9), and III (40+).
How do I calculate BMI with pounds and inches?
The traditional imperial shortcut is weight in pounds times 703, divided by height in inches squared. This calculator instead converts your pounds and inches to kilograms and meters exactly, which gives the same result to within rounding.
Why does BMI call me overweight when I'm athletic?
BMI only compares weight to height — it can't tell whether the weight is muscle or fat. Muscular people often land in the overweight band while lean, which is why BMI is a screening figure rather than a body-composition measurement.