Health
BMI Calculator
Calculate your Body Mass Index and see which weight range you fall into. Supports metric and imperial units.
Guide
How to use the BMI Calculator
The BMI Calculator helps you make a quick estimate, compare scenarios, and understand the numbers behind the result. It is designed for fast planning, with enough context to make the answer useful instead of just a number.
- Enter current measurements as accurately as possible, using the unit system that fits you best.
- Compare the result with the displayed ranges or targets to understand the estimate in context.
- Adjust assumptions such as activity level, sex, age, or goal where the calculator supports them.
Method
How this calculator works
It divides weight in kilograms by height in meters squared and maps the result to common BMI categories.
This calculator is useful for a quick body-size screening estimate using the standard BMI formula.
Because assumptions matter, try a few values that represent optimistic, typical, and conservative cases.
Health calculators are screening and planning tools, not medical advice. They cannot replace a clinician's evaluation.
Example
Worked example
Someone 5'10" (178 cm) weighing 185 lb (84 kg) has a BMI of about 26.5 — in the overweight range, which starts at 25. For that height, the healthy-weight band of 18.5–24.9 corresponds to roughly 129–174 lb (59–79 kg), so the calculator also shows how far you are from each boundary.
FAQ
Common questions
What BMI counts as overweight?
For adults, the standard WHO categories are: under 18.5 underweight, 18.5–24.9 healthy weight, 25–29.9 overweight, and 30 or above obese. The thresholds are the same for men and women.
Is BMI accurate for athletes and muscular people?
No — BMI cannot tell muscle from fat, so muscular people often score as overweight while carrying little body fat. For body composition, a body fat measurement (like the Navy method) is more informative; BMI is best as a quick population-level screen.
Does BMI work the same for children?
No. Children and teens are assessed with age- and sex-specific BMI percentiles rather than the fixed adult cutoffs. This calculator uses the adult formula and categories.
What information do I need for the BMI?
You usually need height and weight in metric or imperial units. You can change the inputs and recalculate as many times as needed.
How does the BMI calculate the result?
It divides weight in kilograms by height in meters squared and maps the result to common BMI categories.
Are the results exact?
Health calculators are screening and planning tools, not medical advice. They cannot replace a clinician's evaluation.
Related
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Sources