BMI Calculator — Calculate Your Body Mass Index

BMI

Your details

Choose your unit system and adjust the sliders or type your own numbers.

Heightcm

120 cm220 cm

Weightkg

30 kg150 kg

Your BMI

1518.5253040

Underweight< 18.5

Normal18.5 – 24.9

Overweight25 – 29.9

Obese30+

BMI is a screening tool, not a diagnosis. It doesn't account for muscle mass, bone density, or body composition.

What is BMI, and how is it calculated

Body Mass Index is a quick screening number that relates your weight to your height. It doesn't measure body fat directly, but it's a widely used starting point for gauging whether your weight falls in a healthy range.

Enter your details

Height and weight, in metric or imperial units.

Calculator does the maths

It applies the standard WHO BMI formula used worldwide.

See where you stand

Your BMI number plus which category it falls into.

The BMI formula

BMI = weight (kg) ÷ height (m)²

weight = your body weight in kilograms

height = your height in metres, squared

A worked example

A person who is 170 cm tall and weighs 65 kg works out like this:

Height	170 cm (1.70 m)
Weight	65 kg
Height squared	2.89 m²
BMI	≈ 22.5
Category	Normal weight

A BMI of 22.5 sits comfortably inside the 18.5–24.9 normal range — being far outside this band on either side is linked to higher health risks.

Frequently asked questions

What is a healthy BMI range?

For most adults, a BMI between 18.5 and 24.9 is considered a normal, healthy weight range according to WHO guidelines.

Is BMI accurate for everyone?

Not entirely. BMI doesn't distinguish between muscle and fat, so athletes or very muscular people can show a higher BMI without excess body fat. It's also less reliable for elderly people, pregnant women, and growing children.

What should I do if my BMI is outside the normal range?

Treat it as a starting point, not a verdict. Talk to a doctor or dietitian who can look at your full health picture before making any changes.

Does BMI differ for men and women?

The formula is the same for everyone, but body composition naturally differs between men and women, so the same BMI can mean a different body fat percentage for each.

Want the full health picture?

BMI is just one number — pair it with a doctor's advice for the full story.

Know your BMI before your next checkup

Your details

What is BMI, and how is it calculated

Frequently asked questions

Want the full health picture?