BMI Calculator

Estimate your Body Mass Index in metric or imperial units and see which standard category it falls in.

Height (cm)

Weight (kg)

BMI: –

This is an educational estimate for adults and is not medical advice. BMI does not distinguish muscle from fat. Consult a healthcare professional about your health.

🔒 Nothing you enter is sent anywhere or stored. All processing happens in your browser.

Features

Metric or imperial

Enter height and weight in centimetres and kilograms, or feet, inches and pounds — the BMI is the same either way.

Instant category

See which standard WHO category your BMI falls in — underweight, normal, overweight or obese.

Clear, simple result

Get a single BMI number plus its meaning, with no clutter.

Private and in-browser

Your height and weight are never uploaded — the calculation runs on your device.

How it works — in four simple steps

No signup, nothing to install — it all runs in your browser.

Step 01

Pick your units

Choose Metric or Imperial to match the numbers you have.

Step 02

Enter height and weight

Type your height and weight in the selected units.

Step 03

Read your BMI

See your BMI value and the category it lands in.

Step 04

Use it as a guide

Treat the result as a general screening figure, not a diagnosis.

How it works

Body Mass Index is a simple screening number that relates your weight to your height. In metric units the formula is weight in kilograms divided by height in metres squared; in imperial units it's 703 times weight in pounds divided by height in inches squared. Both give the same BMI value.

The widely used adult categories are: underweight below 18.5, normal weight from 18.5 to 24.9, overweight from 25 to 29.9, and obese at 30 and above. This tool shows your value and highlights the matching category with a colored badge.

BMI is a population-level screening tool, not a diagnosis. Because it uses only height and weight, it can't tell muscle from fat — very muscular people may read as "overweight" despite low body fat, and it isn't validated for children, pregnancy, or the elderly in the same way. Treat the number as one rough data point and speak with a healthcare professional about your individual health.

Examples

175 cm, 70 kg → BMI 22.9 → Normal weight

5 ft 9 in, 154 lb → BMI 22.7 → Normal weight

160 cm, 80 kg → BMI 31.3 → Obese (screening category)

Frequently asked questions

What BMI is considered healthy?

For most adults, a BMI between 18.5 and 24.9 is labelled 'normal weight'. This is a general screening range, not a personal health verdict.

Is BMI accurate for athletes?

Not reliably. BMI counts muscle and fat the same way, so muscular people can score as 'overweight' despite being lean. Body-composition measures are better for athletes.

Does this work for children?

No. Children and teens use age- and sex-specific BMI percentiles, which this adult calculator doesn't apply. Consult a paediatric chart or professional.

Is any of my data saved?

No. Your height and weight are used only to compute BMI in your browser and are never stored or sent anywhere.