BMI Calculator

Free BMI calculator. Calculate your Body Mass Index, ideal weight range, and estimated body fat percentage instantly.

✓ Free to use ✓ Instant results ✓ Mobile friendly ✓ No sign-up needed

Weight (kg)

Height (cm)

Age

Biological Sex

Your BMI

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Understanding BMI

Body Mass Index (BMI) is a measure of body weight relative to height. It is a widely used screening tool to identify whether a person is at a healthy weight, overweight, or underweight.

BMI Categories (WHO Standard)

Under 18.5: Underweight
18.5 – 24.9: Healthy weight
25 – 29.9: Overweight
30 and above: Obese

Limitations of BMI

BMI does not account for muscle mass, bone density, or fat distribution. Athletes and muscular individuals may have a high BMI but low body fat. Always consult a healthcare professional for a full assessment.

Frequently Asked Questions

Is BMI accurate for everyone?+

BMI is a useful screening tool but not a definitive health measure. It can overestimate body fat in athletes and underestimate it in older adults with low muscle mass.

What is the healthiest BMI?+

A BMI between 20 and 22.9 is generally associated with the lowest health risks for most adults, though optimal ranges vary by age, sex, and ethnicity.

How is body fat percentage estimated?+

The calculator uses the Deurenberg formula: Body Fat % = (1.20 × BMI) + (0.23 × age) − (10.8 × sex) − 5.4, where sex = 1 for male and 0 for female.