Body Mass Index is weight in kg divided by height in metres squared (kg/m²), a population screening metric.

Why might BMI misclassify athletes?

Muscle is denser than fat; high lean mass can raise BMI without excess body fat.

Different thresholds by age?

Adult cut-offs differ from children’s percentiles. This calculator follows common adult bands unless labeled otherwise.

No. It’s one screen among many—waist circumference, blood work, and history matter.

Temporary weight change affects BMI; clinical context matters.

Inputs are processed in your browser and are not sent to our servers.

Calculate Body Mass Index (BMI) with metric or imperial units and see category ranges.

Weight (kg)Height (cm)

BMI

Informational only; verify critical results independently.

Measure or estimate your height and weight using the same units the tool expects.
Enter height in centimetres or feet/inches, and weight in kilograms or pounds.
Submit or let the tool compute; BMI = weight / height² in consistent units.
Read the numeric BMI and the broad category band (underweight through obese).
If you change units, re-enter values—don’t mix metres with pounds without converting.
Use as a screening snapshot, not a diagnosis; talk to a clinician about health goals.

What is BMI?: Body Mass Index is weight in kg divided by height in metres squared (kg/m²), a population screening metric.
Why might BMI misclassify athletes?: Muscle is denser than fat; high lean mass can raise BMI without excess body fat.
Different thresholds by age?: Adult cut-offs differ from children’s percentiles. This calculator follows common adult bands unless labeled otherwise.
Is BMI a medical diagnosis?: No. It’s one screen among many—waist circumference, blood work, and history matter.
Pregnancy or swelling?: Temporary weight change affects BMI; clinical context matters.
Privacy?: Inputs are processed in your browser and are not sent to our servers.

Last updated: 2025-09-15