Free calculators

All calculators

BMI calculatorWeight and height to BMI and the usual adult range.TDEE calculatorDaily energy in kcal and kJ from age, sex, height, weight and activity.Protein calculatorThe national reference amount for your age, sex and weight.Macro calculatorCalories to grams of protein, carbs and fat.Calorie calculatorDaily calories to keep, lose or gain weight, with safe limits.Calorie deficit calculatorA gentle deficit with a safe floor.kJ to calories converterKilojoules to kilocalories and back.Water intake calculatorA guideline amount of fluid a day.Sleep cycle calculatorBedtimes and wake times from sleep cycles.Habit streak plannerHow long until a habit has run 66 days.

What these calculators are for

These ten calculators answer the questions people most often ask about food, weight, sleep, water and habits: what is my BMI, how much energy do I use, how many calories should I eat, how much protein do I need, what are my macros, how much should I drink, when should I go to bed, and how long is my streak. They run in your browser, they work in kilograms or pounds and in kilojoules or calories, and nothing you type is saved or sent.

They are written for healthy adults aged 19 and over. Every formula is shown with a worked example and its source, and every result is an estimate, not advice for you personally.

The calculators build on each other

Most of the food calculators are one chain, so use them in this order. Start with the TDEE calculator, which estimates your daily energy: Mifflin and St Jeor resting energy multiplied by an activity factor from 1.2 to 1.9. For a 30 year old man of 80 kg and 180 cm who is moderately active that is about 2,759 kcal.

The calorie calculator and the calorie deficit calculator turn that into a target, never below 1,200 kcal a day for women or 1,500 kcal for men. The protein calculator gives the national reference amount, 0.84 g per kg for men and 0.75 g per kg for women aged 19 to 70. The macro calculator turns your calories into grams, at 4 kcal per gram for protein and carbohydrate and 9 for fat. The kJ converter turns it all into the kilojoules an Australian label uses, where 1 kcal is 4.184 kJ.

Which calculator should I use?

• I want one number for how much I burn: the TDEE calculator.
• I want a daily calorie target to keep, lose or gain slowly: the calorie calculator.
• I want a gentle deficit with a safe floor: the calorie deficit calculator, with a gentle 300 kcal or a moderate 550 kcal option.
• I want grams of protein: the protein calculator.
• I want grams of protein, carbs and fat: the macro calculator.
• I want to know if my BMI is in the usual adult range of 18.5 to 24.9: the BMI calculator, and then read what BMI misses.
• I want to know how much to drink: the water intake calculator, 2.6 litres for men and 2.1 litres for women, counting all drinks.
• I want bedtimes that fit whole sleep cycles: the sleep calculator.
• I want my streak with rest days: the habit streak calculator.
• I have a food label in kilojoules: the kJ to calories converter.

How we make the numbers, and their limits

Every calculator uses one shared piece of maths, tested against known answers, so the same inputs give the same result on every page. The sources are named on each page and collected on the sources page, and how we calculate explains the formulas in plain words.

The limits matter as much as the numbers. BMI uses only height and weight, so it cannot tell muscle from fat or show where fat sits, and the World Health Organization uses different cut points for Asian populations. Calorie estimates can be out by a few hundred kcal for a real person. Treat a result as a starting point and watch your own results over a few weeks.

Where the Daily Journal fits, and what it does not do yet

If you want to keep a result, the Daily Journal is where you can track what happened next: Today logs food, drinks and exercise, Home shows the trend, and the Food page shows calories and main nutrients. A free account takes about a minute.

The calculators do not yet save into the app automatically, and the app does not yet use your calculated target as a daily calorie ring. The calorie counter and weight loss journal pages show what that could look like.

One person through all ten calculators

A worked example helps more than a description. Take a woman aged 35, 165 cm and 68 kg, who trains three to five days a week. The BMI calculator gives 25.0, at the top edge of the usual adult range of 18.5 to 24.9. The TDEE calculator gives resting energy of about 1,375 kcal and a daily energy use of about 2,130 kcal, which is about 8,912 kJ.

The calorie calculator then shows about 2,130 kcal to keep her weight and about 1,600 kcal to lose about 0.5 kg a week, well above the 1,200 kcal floor for women. The protein calculator gives 51 g a day at the reference 0.75 g per kg. At a 25, 45 and 30 percent split, 2,130 kcal is about 133 g of protein, 240 g of carbohydrate and 71 g of fat.

The water calculator gives 2.1 litres, about 8.4 glasses of 250 mL, counting every drink. The sleep calculator, for a 6:30 am wake, gives 10:45 pm for five cycles, 9:15 pm for six and 12:15 am for four. These are example numbers for one made up person, not a recommendation for you.

Using the calculators on your phone

Each calculator is a single short form that works on a phone without signing in or installing anything. Type your numbers, tap the result, and use the units you prefer. Because nothing you type is saved or sent, you can close the page and your numbers are gone, so write the result down or keep it in the Daily Journal.

If a result looks surprising, check the inputs first: height in centimetres or inches, weight in kilograms or pounds, and the activity level, which is the input people get wrong most often.

Keep going

• Free toolTDEE calculatorOpen →
• Free toolCalorie calculatorOpen →
• Free toolCalorie deficit calculatorOpen →
• Free toolProtein calculatorOpen →
• Free toolMacro calculatorOpen →
• Free toolBMI calculatorOpen →
• Free toolWater intake calculatorOpen →
• Free toolSleep calculatorOpen →
• Free toolHabit streak calculatorOpen →
• Free toolkJ to caloriesOpen →
• GuideHow to calculate TDEEOpen →
• GuideHow to calculate BMIOpen →
• GuideBMI limitsOpen →
• GuideHow to calculate macrosOpen →
• GuidekJ vs caloriesOpen →
• GuideAll guidesOpen →
• ReadCalorie counter appOpen →
• ReadWeight loss journalOpen →
• ReadHow we calculateOpen →
• ReadSourcesOpen →
• ReadHealth disclaimerOpen →