About this tool
A calorie calculator estimates your Total Daily Energy Expenditure (TDEE) — the total number of calories your body burns in a day. TDEE is composed of four elements: Basal Metabolic Rate (BMR, 60–75%), Thermic Effect of Food (TEF, ~10%), Exercise Activity Thermogenesis (EAT, 5–15%), and Non-Exercise Activity Thermogenesis (NEAT, 10–20%).
Our Calorie Calculator uses the Mifflin-St Jeor equation — validated as the most accurate standard formula by the Academy of Nutrition and Dietetics. For individuals who know their body fat percentage, the Katch-McArdle formula is also available for lean-body-mass-based precision.
Whether your goal is weight loss (calorie deficit), weight maintenance, or muscle building (calorie surplus), this tool calculates exact daily targets alongside macronutrient distributions (protein, carbs, and fats) tailored to your goal and activity level.
Practical Usage Examples
Step-by-Step Instructions
Select your biological sex, age, height, and current weight.
Choose your daily activity level from sedentary to extra active.
Select your primary goal: Weight Loss (-500 kcal/day), Extreme Weight Loss (-1000 kcal/day), Maintenance, or Muscle Gain (+300 to +500 kcal/day).
Optional: Enter your body fat percentage for Katch-McArdle calculation.
Click "Calculate" to see your BMR, TDEE, goal calories, and macro breakdown.
Core Benefits
Dual formula support: Mifflin-St Jeor and Katch-McArdle for high accuracy.
Goal-specific targets: Weight loss, maintenance, and muscle building.
Complete macro distribution breakdown (protein, carbs, fats).
Activity level multipliers ranging from sedentary to extreme athlete.
100% client-side — your personal health data stays in your browser.
Free, no signup, works offline after first load.
Frequently Asked Questions
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to keep organs functioning. TDEE (Total Daily Energy Expenditure) is BMR plus all calories burned through daily movement, work, and exercise. TDEE is the number you baseline against for weight targets.
A safe, sustainable calorie deficit is 300 to 500 calories below your TDEE, producing ~0.5 to 1 lb (0.25 to 0.5 kg) of fat loss per week. Deficits exceeding 1,000 calories can cause muscle loss, nutrient deficiencies, and metabolic slowdown.
Mifflin-St Jeor is the gold standard for the general population because it relies on total weight, height, and age. Katch-McArdle is more accurate if you know your exact body fat percentage, as it calculates BMR strictly from Lean Body Mass.
For general health, 0.8g per kg of body weight is the minimum. For active individuals or those in a calorie deficit trying to preserve muscle, 1.6g to 2.2g per kg (0.7g to 1.0g per lb) of total body weight is recommended.
Yes. All calculations happen locally inside your browser. No health, weight, or demographic data is ever sent to a server.