Calorie calculator
Find out how many calories your body uses each day, and how many to eat for your goal. The calculator uses the Mifflin-St Jeor equation, the formula most often used by dietitians, because studies have found it more accurate than the older Harris-Benedict formula.
Uses a standard published formula, explained below. The result is an estimate, not medical advice, and its limits are explained further down the page.
About you
Daily calorie target
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BMR (at complete rest)
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TDEE (maintenance calories)
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Protein
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Carbohydrate
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Fat
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Show the working
—A screening estimate, not a prescription. Individual energy needs vary by ten to fifteen percent from any equation's prediction, and more in the presence of thyroid conditions, medication, pregnancy or a history of dieting. If you have a medical condition or a history of disordered eating, or if you are pregnant or breastfeeding, speak to a doctor or registered dietitian before changing your intake.
BMR and TDEE explained
BMR, your basal metabolic rate, is the energy your body uses at complete rest to keep your heart beating, your lungs working and your temperature steady. It usually makes up about 60% to 70% of the calories you use in a day, which surprises people who assume exercise is the biggest part.
TDEE, your total daily energy expenditure, is your BMR multiplied by an activity factor. These are your maintenance calories: if you eat this amount, your weight should stay roughly the same.
This calculator uses the Mifflin-St Jeor equation:
BMR = 10w + 6.25h − 5a + 5 (men) or − 161 (women)
Here w is your weight in kilograms, h is your height in centimeters and a is your age in years.
Choosing your activity level
The BMR part of the calculation is fairly reliable. Most of the error comes from the activity level, because people tend to overestimate how active they are.
The activity levels are also broad. Someone who trains hard four times a week but sits at a desk for the rest of the day can burn fewer calories than someone who never exercises but is on their feet at work all day. Everyday movement such as walking, standing and fidgeting varies a lot from person to person, and a calculator like this cannot see it.
If you are not sure which level fits, choose the lower one. Overestimating your activity is the more common mistake, and it is the one that quietly stops your progress.
Calories for weight loss: why 0.5 kg a week
One kilogram of body fat holds roughly 7,700 calories, so eating about 500 calories a day less than your TDEE leads to a loss of around half a kilogram a week. That is a useful figure for planning, but it is not an exact rule, because weight loss is never perfectly steady and the body adapts.
As you lose weight, your BMR falls because there is less body to maintain. You also tend to burn fewer calories through movement, partly because a lighter body takes less energy to move and partly because people move around less without noticing. That is why a calorie target that worked at first can stop working, and why you should recalculate as your weight changes.
Losing weight faster is not better. Very large calorie deficits cause you to lose more muscle along with the fat, and they are much harder to keep up. Being able to stick with a plan is what matters most for long-term results.
For safety, the calculator never sets a target below 1,500 calories a day for men or 1,200 for women, and it tells you when that limit has been applied. It also does not suggest a weight loss target if your BMI is already below 18.5.
About the macro split
The protein figure is about 1.6 grams per kilogram of body weight, which is within the range commonly recommended for people who are active or eating less to lose weight. Fat is set at about 27% of your calories, comfortably above the minimum your body needs. Carbohydrates make up the rest.
This is one sensible split among many, not the only right answer. For most people, a plan they can stick to matters more than the exact balance of protein, fat and carbohydrates.
Frequently asked questions
What are maintenance calories?
Maintenance calories are the number of calories you need each day to keep your weight the same. They are the same as your TDEE, which this calculator shows as your maintenance level.
What is TDEE?
TDEE stands for total daily energy expenditure. It is all the calories your body uses in a day, including your basic metabolism, digesting food, exercise and everyday movement.
What is the difference between BMR and TDEE?
BMR is the energy your body uses at complete rest. TDEE is your BMR plus everything else you do during the day, so it is always higher.
How many calories do I need to cut to lose 1 kg?
About 7,700 calories, so a deficit of around 500 calories a day leads to roughly half a kilogram a week. Treat this as a planning figure, not an exact rule.
Why does another calculator give me a different number?
Calculators use different equations, such as Mifflin-St Jeor, Harris-Benedict or Katch-McArdle, and different activity multipliers. Every one of them is an estimate with some margin of error.
How accurate is this calculator?
For most people, the estimate is within about 10% to 15% of their real energy needs, but individuals vary. Use it as a starting point and adjust based on what actually happens to your weight over two to three weeks.
Should I recalculate as my weight changes?
Yes. Your BMR falls as you lose weight, so a target set at your starting weight gives a smaller deficit over time. Recalculating every few kilograms keeps your target accurate.