Find your daily calorie needs with the Mifflin-St Jeor formula. Enter your details and activity level to see calories for maintaining, losing or gaining weight.
1. Enter your age, gender, weight and height. 2. Choose your activity level. 3. Click Calculate Calories.
A calorie is a unit of energy, and your body burns calories all day, even when you are sleeping. A calorie calculator estimates how many calories you need each day to keep your current weight, lose weight or gain weight. It uses your age, sex, weight, height and activity level, and the Mifflin-St Jeor formula, which dietitians use around the world. Enter your details in this free calorie calculator and it shows your daily calorie target, plus lower targets for losing weight and a higher target for gaining weight.
Counting calories is one of the simplest ways to manage weight, because weight change comes down to energy in versus energy out. If you eat more calories than you burn, you gain weight. If you eat fewer, you lose weight. Knowing your daily number takes away the guesswork: you can plan meals, choose snacks and set a realistic goal. This calculator is used by people starting a diet, going to the gym, training for a sport, or simply trying to eat a balanced diet.
Take a 30-year-old man who weighs 70 kg, is 175 cm tall and is moderately active (exercises 3 to 5 days a week). His BMR, the calories his body burns at rest, is 10 times 70 plus 6.25 times 175 minus 5 times 30 plus 5, which is about 1,649 calories. Multiply by the activity factor 1.55 and his daily need is about 2,556 calories to stay the same weight. To lose weight slowly he would aim for about 2,306 calories a day, and to lose weight faster, about 2,056. A 28-year-old woman who weighs 60 kg, is 165 cm tall and is lightly active needs about 1,829 calories a day.
The calculator first finds your BMR (Basal Metabolic Rate) with the Mifflin-St Jeor equation. For men: BMR = 10 times weight in kg, plus 6.25 times height in cm, minus 5 times age in years, plus 5. For women: the same, but minus 161 instead of plus 5. Then it multiplies BMR by an activity factor: 1.2 for a sedentary life, 1.375 for light activity, 1.55 for moderate activity, 1.725 for very active people, and 1.9 for extra active people with a physical job. The result is your TDEE, your total daily energy expenditure.
Be honest about activity. Most people overestimate how active they are, so choose the lower level if you are unsure. Aim for slow weight loss. Losing about 0.5 kg a week, by eating about 500 fewer calories a day, is safer and easier to keep up than a crash diet. Weigh food for a week. Most people guess portion sizes wrong, so weighing food for a few days shows where the extra calories really come from. Do not go too low. Very low calorie diets can make you tired and ill, so most adults should not go below about 1,200 calories a day without a doctor's advice. Recheck after you change weight. As you lose or gain weight, your calorie need changes, so recalculate every month or two.
Take a woman who is 28 years old, weighs 60 kg and is 165 cm tall, and exercises lightly one to three days a week. Her BMR is 10 times 60, plus 6.25 times 165, minus 5 times 28, minus 161, which is 1,330 calories per day at rest. Multiply by the lightly active factor of 1.375 and her daily need is about 1,829 calories to maintain her weight. To lose weight slowly she could aim for about 1,579 calories per day. Enter the same numbers in the calculator above and check that your result matches.
Overstating your activity. Most people choose a higher activity level than they really have, which makes the calorie target too high. Be honest. Using the wrong weight unit. The calculator needs kilograms: 70 kg is not 70 pounds. Eating far too little. Cutting 1,000 calories a day is not healthy for most people; a cut of 250 to 500 is safer. Forgetting drinks and snacks. Juices, soft drinks and snacks add hundreds of calories that people often forget to count. Treating the result as exact. The calculator gives an estimate; your real need depends on your body, your job and your health.
Pro Tip: Track what you eat for one week and compare it with the calculator's number. Small, steady changes work better than a sudden strict diet.
Note: This calculator gives general information only. It is not medical advice. If you have a health condition or want to lose a lot of weight, talk to a doctor or a dietitian first.
What is BMR? Basal Metabolic Rate is the number of calories your body burns at complete rest, just to keep you alive: breathing, keeping your heart beating and keeping your body warm. It is the biggest part of your daily calorie use.
What is TDEE? Total Daily Energy Expenditure is your BMR plus the calories you burn by moving, working and exercising. It is the number of calories you need each day to stay at your current weight.
How many calories should I eat to lose weight? Eating about 250 to 500 calories less than your daily need each day usually leads to steady, safe weight loss of about 0.25 to 0.5 kg a week. Faster loss is possible but harder to keep up.
Is this medical advice? No. This is an estimate for general information only. If you have a health condition, are pregnant, or want to lose a lot of weight, talk to a doctor or a dietitian first.
Why does the calculator ask for my sex? Men and women have different average body composition, so the Mifflin-St Jeor formula uses a different constant for each. That is why the same weight and height give a different result for a man and a woman.
How accurate is this calorie calculator? It is a good estimate for most people, usually within about 10 percent. Real calorie needs also depend on muscle mass, health and daily habits, so treat the result as a starting point and adjust it after a few weeks.
How often should I recalculate my calorie needs? Recalculate every few months, or after your weight changes by about 5 kilograms. As you lose or gain weight, your body needs fewer or more calories, so the number that was right three months ago may be too high or too low now.
Does exercise change my calorie need? Yes. The activity level you choose multiplies your BMR, so more exercise means a higher daily calorie need.