Free health, fitness and nutrition calculators
Ten calculators that run entirely in your browser — no sign-up, no uploads, nothing stored on our servers. Every result shows the formula behind it so you can check the maths yourself.
All calculators
- BMI CalculatorFree BMI calculator for metric and imperial units. Instantly see your body mass index, which weight category you fall into, and your healthy weight range.
- Calorie CalculatorFree calorie calculator using the Mifflin-St Jeor equation. See your daily calorie needs to maintain, lose or gain weight, plus your BMR.
- BMR CalculatorCalculate your basal metabolic rate with the Mifflin-St Jeor equation, or use Katch-McArdle if you know your body fat percentage.
- Body Fat CalculatorEstimate your body fat percentage from waist, neck and hip measurements using the US Navy circumference method. Works in metric and imperial.
- Ideal Weight CalculatorSee your estimated ideal weight using the Devine, Robinson and Hamwi formulas, plus the BMI-based healthy weight range for your height.
- Macro CalculatorFree macro calculator. Get your daily protein, carbohydrate and fat targets in grams based on your TDEE and whether you want to lose fat, maintain or build muscle.
- Water Intake CalculatorCalculate how much water to drink each day based on your body weight, exercise and climate. Results in litres, glasses and fluid ounces.
- Sleep CalculatorEnter a wake-up time and see the best times to fall asleep, or find out when to wake up if you sleep now. Based on 90-minute sleep cycles.
- Protein Intake CalculatorCalculate your daily protein target in grams based on body weight and activity level, with per-meal breakdowns for 3 or 4 meals.
- Caffeine CalculatorCalculate your personal daily caffeine limit based on body weight and sensitivity, and see how many coffees, teas or energy drinks that equals.
- Food ScannerPhotograph a meal and get an AI estimate of its calories and macros.
Why we show the formula
Most health calculators give you a number and nothing else. Every tool on Calorie Deck explains the equation it used, who published it, and where it tends to break down. If a formula cannot describe your body well, you should be able to see why — and judge the result accordingly.