Health calculators
Check your body mass index and estimate how many calories your body uses each day. Both are screening tools, and each page explains what the number leaves out.
What the health calculators do
The BMI calculator divides your weight by your height squared and places the result in a standard range. The calorie calculator estimates your basal metabolic rate with the Mifflin-St Jeor equation and multiplies it by an activity factor to give a maintenance figure.
Use the numbers as a starting point
BMI cannot tell muscle from fat, and calorie estimates can differ from your real needs by several hundred a day. If you are unsure which activity level to choose, pick the lower one and adjust after a few weeks of real results.
Neither tool is a diagnosis. For decisions about weight, diet or medical conditions, speak to a doctor or registered dietitian.
Frequently asked questions
Is BMI accurate for everyone?
No. BMI is a quick screening number. It does not separate muscle from fat, so athletes and older adults may get a result that does not reflect their health.
Can I use metric or imperial units?
Yes. The BMI calculator accepts kilograms and centimetres, or pounds and inches.
Do the health calculators store my details?
No. The calculations run in your browser and nothing you type is sent to our servers.