A calorie calculator turns weight goals into clear daily numbers. Whether you want to lose fat, maintain your current weight, or gain lean muscle, knowing your target calorie intake is the most important step. Calories are the fuel your body runs on — eat more than you burn and you gain weight, eat less and you lose weight, eat the same and you stay the same.

Our calculator estimates your maintenance calories using your Basal Metabolic Rate combined with an activity multiplier, then provides specific targets for slow weight loss, moderate weight loss, weight maintenance, and weight gain. The results are personalized to your age, gender, height, weight, and how active you are.

How calorie needs are calculated

Your daily calorie needs depend on two things: your Basal Metabolic Rate (BMR) and your activity level. BMR is what your body burns at complete rest. Activity adds on top of that — walking, working, exercise, even fidgeting all burn additional calories.

We calculate BMR with the Mifflin-St Jeor formula, then multiply by an activity factor: 1.2 for sedentary office work and no exercise, 1.375 for light activity (1-3 workouts per week), 1.55 for moderate activity (3-5 workouts per week), 1.725 for high activity (6-7 workouts per week), and 1.9 for very high activity (athletes or physical jobs combined with intense training).

The result is your TDEE (Total Daily Energy Expenditure) — the calories you need to maintain your current weight. To lose weight, eat below TDEE. To gain weight, eat above. The standard rule is that 3,500 calories equals one pound of body fat, so a 500-calorie daily deficit produces about one pound of loss per week.

Setting realistic weight loss calorie targets

A safe, sustainable weight loss rate is 0.5-2 pounds per week. To lose 1 pound per week, eat 500 calories per day below your TDEE. To lose 2 pounds per week, eat 1,000 below — though this is hard to sustain for most people and can lead to muscle loss if not paired with strength training and adequate protein.

Avoid eating below 1,200 calories per day for women or 1,500 calories for men without medical supervision. Going too low slows metabolism, causes muscle loss, increases hunger, and is difficult to maintain long enough to reach your goal. Slow and steady wins this race.

If your TDEE is too low to support a healthy deficit (e.g., a small, sedentary person), the answer is to add activity rather than cut calories further. Walking 30 minutes daily can add 150-200 calories of expenditure without needing to eat less.

Calorie quality matters too

While calorie quantity drives weight change, calorie quality drives health and how you feel. 1,800 calories from whole foods (lean protein, vegetables, whole grains, healthy fats) supports energy, satiety, and muscle maintenance far better than 1,800 calories from processed snacks and sugary drinks.

Aim for 0.7-1 gram of protein per pound of body weight, especially when in a calorie deficit, to preserve muscle. Fill at least half your plate with vegetables and fruits. Choose whole grains over refined ones. These habits make any calorie target easier to stick to and produce better body composition results.

How to use this calculator

1. Select your gender.
2. Enter your age.
3. Enter your height and weight.
4. Choose your activity level.
5. Optionally select your goal (lose, maintain, gain).
6. Click Calculate to see your daily calorie targets.

Frequently asked questions