About this tool
Looking after your weight usually starts with two numbers: your body mass index, which tells you where you are against the WHO ranges, and the calories your body burns in a day, which tell you how much to eat to lose, keep or gain weight. Here both live together. Choose what you want to calculate at the top. The height and weight you type in one go along to the other, and everything is worked out in your browser: nothing is sent to a server or put in the address. These are estimates for healthy adults, not a diagnosis.
How to use it
- 1 Choose at the top: BMI or calories per day.
- 2 Type your height and weight (and, for calories, sex, age and activity).
- 3 Read the result: the BMI range and healthy weight, or the calories to lose, keep or gain weight.
- 4 Switch at any time: height and weight follow you, and each one keeps what you typed while the page is open.
Frequently asked questions
Are my height and weight saved or sent anywhere?
No. They stay in your browser. They are not sent to a server, not saved and not put in the page address.
Do the BMI calculator and calorie calculator pages still exist?
Yes. Each one opens this same page on its own calculator.
Which formulas are used?
BMI is weight divided by height squared, with the World Health Organization ranges. Calories use the Mifflin-St Jeor equation for the resting rate, times your activity level.
Where are the pregnancy calculators?
Weeks of pregnancy, weight gain in pregnancy and the menstrual cycle have their own page, Pregnancy and cycle, because BMI and the usual calorie targets do not apply during pregnancy.
Embed this tool
Add this free tool to your own website — copy the code below. It stays up to date automatically.
Tools for your site →