BMI Calculator
Enter your height and weight to calculate BMI, a general screening measure (not a diagnosis).
Last updated: August 30, 2026
Frequently asked questions
Is BMI accurate for everyone?
No - BMI doesn't distinguish muscle from fat and can be misleading for athletes, older adults, and some body types. It's a screening tool, not a diagnosis.
What counts as a healthy BMI range?
18.5–24.9 is generally classified as the healthy range, under 18.5 as underweight, 25–29.9 as overweight, and 30+ as the obesity range - but these cutoffs are population averages, not individual health verdicts.
Does BMI apply the same way to children as adults?
No - this calculator uses the adult BMI formula and adult healthy-range cutoffs; children and teens need age- and gender-specific growth-chart percentiles instead, since healthy body composition changes significantly throughout childhood development.
How is BMI different from body fat percentage?
BMI only uses height and weight, so it can't distinguish muscle from fat - a very muscular person may show a high BMI without excess body fat. Body fat percentage measures the fat portion of your body directly and gives a more accurate picture of body composition than BMI alone.
How do I compute BMI, and is 'body weight index' the same thing?
To compute BMI by hand: divide your weight in kilograms by your height in meters squared (or use weight in pounds divided by height in inches squared, times 703, as this calculator does). "Body weight index" is an informal variant of the same search term - it refers to the same body mass index (BMI) calculation, not a separate metric.
Are 'body index calculator,' 'mass index calculator,' 'biomass index calculator,' 'bio mass index,' and 'corporal mass index' all the same as BMI?
Yes - these are all informal, mistranslated, or misremembered versions of the same search: body mass index (BMI). "Corporal mass index" is a direct translation from Spanish/Portuguese ("índice de masa corporal"/"índice de massa corporal"). This calculator computes standard BMI from height and weight, regardless of which of these phrasings you used to find it.