How to Use the Calorie Calculator
- 1Enter your age, sex, height, and weight.
- 2Select your activity level based on your typical weekly exercise.
- 3Choose your goal (lose, maintain, or gain).
- 4Click Calculate Calories for your personalized daily target.
Understanding Your Calorie Results
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest — just to keep your organs functioning. It accounts for about 60–70% of total daily calorie burn.
TDEE (Total Daily Energy Expenditure) is your BMR multiplied by your activity level. This is how many calories you burn in a typical day and is your "maintenance" calorie level.
The Formula Used
This calculator uses the Mifflin-St Jeor equation, the most widely validated formula for estimating BMR:
- Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5
- Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161
How Fast Can I Safely Lose Weight?
A caloric deficit of 500 calories/day leads to about 1 lb of fat loss per week (3,500 calories = 1 lb). This rate is widely recommended by dietitians as sustainable. Losing more than 2 lbs/week often leads to muscle loss and is not recommended for most people.
How Many Calories to Build Muscle?
Building muscle requires a small calorie surplus — typically 250 to 500 calories above your TDEE — combined with progressive resistance training and enough protein. Eating in a surplus without strength training mostly adds fat, while too large a surplus (1,000+ calories) leads to faster fat gain than muscle gain. A "lean bulk" approach (a modest surplus over several months) is generally more effective for long-term body composition than aggressive bulking.
Why Calorie Needs Vary From Person to Person
Two people with the same age, height, and weight can have noticeably different calorie needs. Muscle mass burns more energy than fat tissue, so a more muscular person typically has a higher BMR. Genetics, hormone levels (especially thyroid function), sleep quality, and even the thermic effect of certain foods all influence daily energy expenditure. That's why this calculator gives you a scientifically grounded starting point — but tracking your weight over 2–3 weeks and adjusting calories up or down by 100–200 is the best way to find your true personal number.
Calories vs. Macros: Which Matters More?
Total calories determine whether you gain, lose, or maintain weight — but macronutrient split (protein, carbs, and fat) affects how that weight changes. Higher protein intake (around 0.7–1g per pound of body weight) helps preserve muscle during a calorie deficit and supports muscle growth during a surplus. The macro breakdown provided by this calculator splits your daily target into protein, carbohydrate, and fat grams based on your goal, so you have a practical daily target — not just a single number.