Calorie Calculator
Estimate your daily calorie needs using the Mifflin-St Jeor equation.
What Is a Calorie Calculator?
A calorie calculator estimates how many calories your body needs each day to maintain its current weight, based on your age, gender, height, weight, and activity level. That maintenance figure — your total daily energy expenditure, or TDEE — is the reference point for every weight goal: eat below it and you tend to lose weight, eat above it and you tend to gain. This calculator does the arithmetic instantly so you can plan meals and targets around a realistic number instead of a guess.
Most people are surprised by their first result. Popular one-size-fits-all advice (such as a flat 2,000 calories for everyone) ignores the fact that a tall, active 25-year-old man and a petite, sedentary 55-year-old woman can legitimately differ by 1,000 calories a day or more. Personalizing the estimate is the entire point.
How to Use the Calorie Calculator
- Enter your age in years.
- Select your gender.
- Enter your height in centimeters and your current weight in kilograms.
- Pick the activity level that best matches a typical week, from sedentary to extra active.
- Click Calculate to see your estimated daily maintenance calories.
How the Estimate Works
The calculator first estimates your basal metabolic rate (BMR) with the Mifflin-St Jeor equation — (10 × kg) + (6.25 × cm) − (5 × age), plus 5 for men or minus 161 for women — then multiplies it by an activity factor. Sedentary living multiplies BMR by about 1.2, while training most days pushes the factor toward 1.7 or higher. A common rule of thumb for goals: a deficit or surplus of roughly 500 calories per day corresponds to about a pound (0.45 kg) of body-weight change per week, though real results vary and slower changes are usually easier to sustain.
Tips for Hitting Your Calorie Target
- Weigh yourself a few times a week and compare two-week averages — daily numbers swing with water, salt, and digestion.
- Choose the activity level for your average week, not your best week; overestimating activity is the most common reason targets fail.
- Prioritize protein and fiber at any calorie level — they keep you full and protect muscle while you lose fat.
How many calories should I eat to lose weight?
A widely used starting point is 300–500 calories below your maintenance estimate, which typically produces steady loss of about 0.25–0.5 kg per week. Very aggressive deficits are harder to sustain and increase muscle loss. Persistent fatigue, hair loss, or stalled progress are signs to eat more or consult a professional.
Why does my result differ from other calculators?
Different calculators use different BMR equations (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle) and different activity multipliers, so results commonly differ by 100–200 calories. That spread reflects genuine uncertainty in estimating any individual's metabolism — treat all of them as approximations and adjust based on your real-world trend.
Do I need to eat back calories burned exercising?
If you selected an activity level that already includes your training, no — the exercise is already counted in the multiplier, and adding it again double-counts. If you chose "sedentary" but work out several times a week, either raise the activity level or add exercise calories back; just don't do both.
Is a calorie just a calorie for weight change?
For the scale, total energy intake is the dominant factor. For health, hunger, and body composition, the source matters a great deal: protein preserves muscle, fiber and minimally processed foods improve satiety, and liquid calories are notoriously easy to over-consume. This calculator addresses the quantity side; quality still counts.