Health and nutrition calculators
These calculators turn a few facts about you, such as your age, sex, height, weight and how active you are, into a daily calorie, macro or water target. They are free to use, work in metric or imperial units, and each page names the formula it is built on so you can check the method for yourself.
If you are starting from scratch, a sensible order is to estimate what you burn in a day with the TDEE calculator, then use the calorie deficit calculator if you want to lose weight, then split that calorie target into grams with the macro and protein calculators. The body measurement tools are for seeing where you are now and for tracking change over time.
Treat every result as an estimate. Formulas describe averages, and your own metabolism, muscle mass and daily movement can put you above or below them. Use the number as a starting point, track what you eat for a few weeks, and adjust to what your weight actually does. Every formula is written out, with a worked example, on how we calculate.
This is general information, not medical advice. If you are pregnant, under 18 or managing a health condition, talk to a doctor or registered dietitian before changing how you eat.
Energy and weight
How many calories you burn, and how many to eat to move your weight.
- TDEE CalculatorEstimates the calories you burn in a day: your BMR from the Mifflin-St Jeor equation, multiplied by an activity factor.
- BMR CalculatorEstimates the calories your body uses at rest with the Mifflin-St Jeor equation, from your weight, height, age and sex.
- Calorie Deficit CalculatorTurns your maintenance calories and a goal weight into a daily calorie target, a weekly rate of loss and a rough timeline.
- Calorie CalculatorTurns your maintenance calories and a goal (lose, maintain or gain) into one daily calorie target, a weekly pace and a per-meal split.
- Weight Loss CalculatorStarts from a goal weight and the weeks you have, and works out the daily calories and deficit it takes, never below the minimum.
- Weight Gain CalculatorAdds a calorie surplus to your maintenance calories and shows the daily target, the weekly gain and the time to a goal weight.
- How Long to Lose WeightDivides the weight you want to lose by a weekly pace to give the weeks and months it takes, with other paces side by side.
- Calorie Cycling CalculatorSplits a weekly calorie target into high and low days that add up to the same week, with the lowest day kept above the minimum.
- Intermittent Fasting CalculatorWorks out your eating window, fasting hours and evenly spaced meal times from a schedule and a first-meal time. A clock, not health advice.
- Weight Loss PercentageGives the percentage of your starting weight you have lost or gained, the weekly rate, and what 5, 10 and 15 percent come to.
- Steps to Calories CalculatorTurns a step count into distance, walking time and calories using your step length, your weight and a walking pace with a Compendium MET value.
- Steps to Distance CalculatorConverts a step count into kilometres and miles from your step length, which it estimates from your height unless you type your own.
Macros
Protein, carbs and fat targets for a daily calorie budget.
- Macro CalculatorSplits a daily calorie target for your goal (lose, maintain or gain) into grams of protein, carbs and fat.
- Protein CalculatorSuggests a daily protein range in grams from your body weight and goal.
- Keto CalculatorSets a daily calorie target for your goal and a net carbohydrate limit you choose, then works out protein and fat grams.
- Cutting Macro CalculatorWorks out the calories for a cut at a deficit you choose, then sets protein by body weight, fat as a share of calories and carbs for the rest.
- Bulking Macro CalculatorWorks out the calories for a bulk at a surplus you choose, then sets protein by body weight, fat as a share of calories and carbs for the rest.
- Carb CalculatorShows the grams of carbohydrate that make up 45 to 65 percent of the calories for your goal, with a per-meal figure.
- Fat Intake CalculatorShows the grams of fat that make up 20 to 35 percent of the calories for your goal, and the saturated fat ceiling inside it.
- Fiber CalculatorWorks out fiber at 14 grams per 1,000 calories for your goal, next to the Adequate Intake for your sex and age.
- Net Carbs CalculatorSubtracts fiber and a share of the sugar alcohols you choose from the total carbohydrate on a label to give net carbs.
Body measurements
Where your weight and body composition sit against common reference points.
- BMI CalculatorWorks out your Body Mass Index and the weight range for your height that falls in the standard BMI categories. It is a screening number, not a diagnosis.
- Body Fat CalculatorEstimates body fat from tape measurements of your neck, waist and (for women) hips, using the U.S. Navy method.
- Ideal Weight CalculatorShows four classic height-based formulas (Devine, Robinson, Miller, Hamwi) next to the weight range that keeps your BMI in the healthy band.
- Lean Body Mass CalculatorEstimates lean body mass from your weight and height with the Boer and Hume formulas, and from a body fat percentage if you know it.
- FFMI CalculatorWorks out your fat-free mass index, and the version adjusted to a height of 1.8 m, from your weight, height and body fat percentage.
- Waist-to-Height Ratio CalculatorDivides your waist measurement by your height, and shows the waist that would be half your height.
- Waist-to-Hip Ratio CalculatorDivides your waist measurement by your hip measurement. It shows the ratio only and applies no cut-off.
Hydration
A daily water target to start from.
- Water Intake CalculatorEstimates a daily water target from your body weight, how much you exercise and the climate you live in.
- Sweat Loss CalculatorEstimates how much you sweated in a session from your weight before and after, the fluid you drank and the urine you passed. An estimate, not hydration advice.
Food maths
Recipes, drinks, caffeine, sugar and energy units, worked out from published values.
- Recipe Calorie CalculatorAdds up the calories, protein, carbs and fat of a recipe from USDA food data, per serving and per 100 g. No AI: every number is a sum.
- Alcohol Calorie CalculatorWorks out the calories in a drink from its volume and ABV, at 7 kcal per gram of alcohol plus its carbohydrate, and shows US standard drinks.
- kJ to kcal ConverterConverts kilojoules to kilocalories and back at 4.184 kJ to the kcal, the factor food labels use.
- Caffeine CalculatorAdds up the caffeine in your coffee, tea, cola and chocolate from USDA values and sets it beside the 400 mg adult reference. For healthy adults only.
- Sugar Intake CalculatorTurns grams of free sugars and your daily calories into a share of energy, beside the World Health Organization guideline on free sugars.
- Calories to Fat CalculatorTurns a calorie deficit or surplus into kilograms and pounds of body fat by the 7,700 kcal per kg rule, with the rule's documented limits.
Keep the numbers working for you
A calculator gives you a target. CalorTracker helps you hit it: log meals by photo, voice or text, and see your calories and macros against the goal you set.
Start free on the web