BMI Calculator
Calculate your Body Mass Index (BMI) in metric or imperial units and see the healthy weight range for your height.
kg
cm
Your BMI
22.9
Healthy weight
- Healthy weight range for your height
- 56.7 to 76.3 kg
BMI is a general guide, not a medical diagnosis.
How is BMI calculated?
Body Mass Index is a simple measure that compares your weight to your height. It is worked out by dividing your weight in kilograms by the square of your height in metres. This calculator accepts either metric (kilograms and centimetres) or imperial (stones, pounds, feet and inches) and converts for you.
As a general guide, a BMI below 18.5 is classed as underweight, 18.5 to 24.9 as a healthy weight, 25 to 29.9 as overweight and 30 or above as obese. The calculator also shows the weight range that would put you in the healthy band for your height.
What BMI does and does not tell you
BMI is a useful, quick indicator for most adults, but it is not a perfect measure of health. It does not distinguish muscle from fat, so very muscular people can have a high BMI while still being healthy, and it is not designed for children, pregnancy or some ethnic groups where different thresholds may apply.
Treat BMI as one general signal rather than a diagnosis. If you have any concerns about your weight or health, speak to a GP or a qualified health professional who can consider your full picture.
Worked example
Someone weighing 70 kg and standing 175 cm tall has a BMI of about 22.9, which is within the healthy range.
For that height, a healthy weight is roughly 57 kg to 76 kg.
Please note: BMI is a general indicator, not medical advice or a diagnosis. Speak to a GP or health professional about any health concerns.
Frequently asked questions
Is BMI accurate for everyone?
It is a helpful general guide for most adults but does not account for muscle, and is not suitable for children, pregnancy or some groups where different thresholds apply.
What is a healthy BMI?
For most adults, a BMI between 18.5 and 24.9 is considered healthy. The calculator shows the weight range that matches this for your height.
Can I use stones and pounds?
Yes. Switch to imperial to enter your weight in stones and pounds and your height in feet and inches.
Should I rely on BMI alone?
No. It is one general indicator. Waist measurement, activity, diet and other factors matter too, and a health professional can give tailored advice.
Figures last reviewed on 13 August 2025.
Related calculators
Age
Work out your exact age in years, months and days from your date of birth, and see how long until your next birthday.
Open calculatorPercentage
Work out percentages quickly: a percentage of a number, what percentage one number is of another, and percentage increase, decrease or difference.
Open calculatorDate Difference
Count the days between two dates, or add and subtract days from a date, with an option to count working days only.
Open calculatorTip
Work out the tip, the total to pay and how much each person owes when splitting a bill.
Open calculator