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BMI Calculator

Find your Body Mass Index and what category it falls into.

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About Health Calculator

BMI is a population screening figure and carries no information about body composition, so it misreads muscular and older bodies in opposite directions. All three outputs are estimates for planning, not a substitute for a clinician.

Calculate your Body Mass Index and see which category it falls into from your height and weight. It runs in your browser as an informational estimate — not medical advice.

Estimate your Body Mass Index, daily calorie needs using the proven Mifflin–St Jeor formula, and a pregnancy due date from your last menstrual period. It brings three common health estimates together so you can plan diet, fitness and milestones quickly.

These figures are informational estimates rather than medical advice — take decisions about your health with a clinician. Calorie targets especially are a starting point to adjust against real results, since activity level is self-reported and easy to overstate.

Learn how this works

Everyday Calculations & Conversions Made SimpleConvert units and time zones, and calculate age, BMI, discounts and loan EMIs — a plain-English guide with free in-browser tools.7 min read

Frequently asked questions

What do the BMI categories mean?

The WHO bands for adults are under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight and 30+ obese. They describe populations, not individuals — a single number cannot tell you whether you personally are healthy.

Why is BMI considered unreliable?

It uses only height and weight, so it cannot distinguish muscle from fat or tell where fat is carried. Muscular people are routinely classed as overweight, and the standard bands were derived largely from European populations — several health bodies use lower thresholds for people of South Asian descent.

Does BMI work for children?

Not in this form. Children are assessed against age- and sex-specific percentile charts, because healthy body composition changes throughout growth. Use a paediatric BMI-for-age chart instead.

Common Use Cases

  • •Getting a rough baseline before a conversation with a doctor
  • •Tracking a broad trend over months rather than a single reading
  • •Understanding where a figure quoted in a health article actually sits

More Health Calculator tools

Health CalculatorCalorie Calculator (BMR & TDEE)Pregnancy Due Date Calculator

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