This calorie calculator estimates how much energy you burn in a day and what to eat to maintain, lose, or gain weight at a steady pace. It uses the Mifflin-St Jeor equation for your resting metabolism, multiplies it by a standard activity factor to get your TDEE, and lays out daily targets for losing or gaining 0.25 to 1 kg (or 0.5 to 2 lb) a week. Targets never drop below common safe minimums, and a macro split turns any target into grams of protein, carbohydrate, and fat.
Every number here is an estimate: metabolism varies from person to person, so use it as a starting point and adjust based on how your weight actually changes. To check where your weight sits relative to your height, try the BMI calculator. The unit converter handles stones, ounces, and other units, and the percentage calculator is handy for working out your own macro ratios. Nothing you enter leaves your browser.
Pairing this with a BMI check? See what BMI can and can't tell you for what that number does and doesn't measure.
Frequently asked questions
How does this calorie calculator work?
It first estimates your basal metabolic rate (BMR), the energy your body uses at complete rest, with the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, plus 5 for men or minus 161 for women. It then multiplies BMR by an activity factor from 1.2 (sedentary) to 1.9 (extra active) to get your total daily energy expenditure, or TDEE. That is your estimated maintenance intake, and the goal targets are built from it.
Why Mifflin-St Jeor instead of Harris-Benedict?
Mifflin-St Jeor was published in 1990 and, in a 2005 review by the American Dietetic Association, was the equation most likely to predict resting metabolic rate within 10 percent of measured values in healthy adults. The older Harris-Benedict equation (1919, revised 1984) tends to overestimate. If you know your body-fat percentage, you can also switch to Katch-McArdle, which works from lean body mass and can be more accurate for very lean or very muscular people. When you add body fat, both results are shown so you can compare them.
How many calories should I cut to lose weight?
A common rule of thumb is that about 7,700 kcal equals one kilogram of body weight, or 3,500 kcal per pound. Losing 0.5 kg a week therefore needs a deficit of about 550 kcal a day, and one pound a week needs about 500. The table shows several paces. Real-world loss usually slows over time as your body adapts, so treat the numbers as a starting point and re-check every few weeks as your weight changes. Faster than about 1 percent of body weight a week is hard to sustain.
Why won't the calculator show a target below 1,200 or 1,500 calories?
Very low intakes make it hard to get enough protein, vitamins, and minerals, and they raise the risk of muscle loss and gallstones. Common guidance is not to go below about 1,200 kcal a day for women or 1,500 for men without medical supervision. When a fast pace would push your target under that line, the calculator shows the minimum instead and marks it with an asterisk. A slower pace, more activity, or a conversation with a dietitian are the safer routes.
Which activity level should I pick?
Most people overestimate. Sedentary (×1.2) means a desk job and little deliberate exercise. Lightly active (×1.375) is light exercise one to three days a week, moderately active (×1.55) is three to five days, very active (×1.725) is hard training six or seven days, and extra active (×1.9) means very hard daily training or a physical job. If unsure, choose the lower option and adjust after two or three weeks of tracking your weight. If it holds steady at the maintenance number, the level you picked is about right.
How are the macro grams calculated?
The macro split takes the calorie target you selected and divides it by percentage: balanced is 20 percent protein, 50 percent carbs, and 30 percent fat; lower carb is 30/20/50; high protein is 35/40/25. Protein and carbohydrate supply about 4 kcal per gram and fat about 9 kcal per gram, so 2,000 kcal on the balanced split is 100 g protein, 250 g carbs, and about 67 g fat. Click a different goal row to recalculate the grams for it.