BMI Calculator
Enter your height and weight to get your Body Mass Index and WHO weight category — instantly.
Your measurements
How BMI is calculated
BMI = weight (kg) ÷ height (m)². With imperial units: BMI = 703 × weight (lb) ÷ height (in)². The WHO categories: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30+ obese.
Frequently asked questions
How is BMI calculated?
BMI = weight in kilograms divided by height in meters squared. With imperial units: BMI = 703 × weight in pounds divided by height in inches squared.
What is a healthy BMI?
The WHO defines 18.5–24.9 as the healthy BMI range for adults. Below 18.5 is underweight, 25–29.9 overweight, and 30 or above obese.
Is BMI accurate?
BMI is a useful screening measure but doesn't distinguish muscle from fat. Athletes and very muscular people may show a high BMI while being healthy.
What should my BMI be at my height?
Multiply your height in meters squared by 18.5 and 24.9 — that gives your healthy weight range. The calculator above computes it for you automatically.
Is BMI different for men and women?
The formula is the same, but women naturally carry more body fat at the same BMI. Some researchers suggest slightly different healthy ranges, but WHO categories apply to all adults.
Does BMI work for children?
Not directly — children's BMI is interpreted as a percentile for their age and sex, not the adult cutoffs. Ask a pediatrician for child assessments.
What is a good alternative to BMI?
Waist-to-height ratio (keep waist under half your height) and body-fat percentage give a fuller picture, especially for muscular builds.