Fitness calculators

Free, accurate and private. Every calculator works in metric, US or UK units, runs entirely in your browser, and shows the formula behind the number.

Calories & energy

Work out your Total Daily Energy Expenditure (maintenance calories) and the targets to lose or gain weight, from the Mifflin-St Jeor equation.

Calculate your Basal Metabolic Rate, the calories your body burns at complete rest, using the Mifflin-St Jeor and Katch-McArdle equations.

Find the calorie deficit to reach your goal weight, and the realistic date you'll get there, at a safe rate that protects muscle.

Estimate calories burned for dozens of activities using research MET values and your bodyweight. Honest numbers, not inflated tracker figures.

Calculate your Body Mass Index and see your category, including the lower ethnicity-adjusted thresholds recommended for Asian and other populations.

Estimate your body fat percentage from simple tape measurements using the US Navy method, and see your fitness category.

Your waist-to-height ratio is a better screen for health risk than BMI. Calculate it and see the NICE health categories in seconds.

Find your healthy weight range for your height, with standard and ethnicity-adjusted BMI ranges plus the classic ideal-weight formulas.

Get your daily protein, carbohydrate and fat targets in grams, based on your calories and goal, using evidence-based protein recommendations.

Calculate your daily protein target in grams from your weight, goal and activity, using evidence-based recommendations for fat loss and muscle.

Estimate how much water to drink a day based on your weight, activity and climate, with the science on hydration and the '8 glasses' myth.

Plan your calories across Suhoor and Iftar during Ramadan, or any eating window, to stay energised and avoid weight gain while fasting.