Simple calculators to understand your numbers.
Free, easy tools to help you make sense of your weight, calories and habits. No sign-up, no jargon — just answer a couple of questions and get your number.
See if you’re eligible for treatmentPick a calculator
Five quick tools, each takes under a minute.
BMI calculator
Work out your Body Mass Index from your height and weight, and see which range you fall into.
Open calculator →Daily calories (TDEE)
Estimate how many calories your body burns in a day, based on your age, size and activity.
Open calculator →Calorie deficit
Find a daily calorie target for steady, sustainable weight loss at a pace that suits you.
Open calculator →Protein target
See a sensible daily protein range to support your muscle and your goals.
Open calculator →Water intake
Get a simple daily water goal based on your weight and how active you are.
Open calculator →These tools give general guidance only and are not medical advice. Everyone is different — for decisions about your health, speak to a qualified clinician.