BMI Calculator

Calculate your Body Mass Index from height and weight, with your category and healthy range.

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BMI Calculator: The Complete Guide

Find your Body Mass Index in seconds. Enter your height and weight in metric or imperial units to see your BMI, which category it falls into, and the healthy weight range for your height.

Who the BMI Calculator is for

Anyone checking whether their weight is in a healthy range for their height as a quick screening step.

How to use the BMI Calculator

  1. Type your values into the fields above — pick your currency or units where the calculator offers them.
  2. Results update automatically as you type; there's no submit button and nothing is sent to a server.
  3. Adjust any input to compare scenarios, then copy the result with a single click.

How it works

BMI = weight (kg) ÷ height (m)². The standard categories are under 18.5 (underweight), 18.5–24.9 (normal), 25–29.9 (overweight), and 30 or more (obese).

Features

  • Metric or imperial units
  • BMI category
  • Healthy weight range
  • Instant result

What BMI does and doesn't tell you

Body Mass Index is a simple ratio of weight to height used to screen for underweight, healthy weight, and overweight at a population level. It's quick and useful, but it doesn't distinguish muscle from fat or account for frame and fat distribution — so very muscular people can read 'overweight' despite low body fat. Treat it as one signal, not a diagnosis.

References & further reading

Frequently Asked Questions

Is BMI accurate for athletes?

Not always — muscle weighs more than fat, so muscular athletes can have a high BMI despite low body fat. Pair BMI with a body-fat or waist measure.

What is a healthy BMI?

For most adults, a BMI between 18.5 and 24.9 is considered healthy. Below 18.5 is underweight and 25 or above is overweight.

Is this calculator free and private?

Yes. It's completely free with no signup, and every calculation runs locally in your browser, so your numbers never leave your device.