Daily Calorie & TDEE Calculator
Calculate your daily energy needs based on the Mifflin-St Jeor Equation.
Understanding Your Calorie Requirements
Food calories are the energy stored in the chemical bonds of the food we consume. This calculator uses the Mifflin-St Jeor Equation, widely considered the most accurate formula for predicting Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) in clinical settings.
BMR vs. TDEE: What's the Difference?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to keep your organs functioning (heart beating, lungs breathing, etc.). It does not include the energy used for walking, talking, or even digesting food.
Total Daily Energy Expenditure (TDEE) is an estimation of how many calories you burn per day when exercise and physical activity are taken into account. This is your "maintenance level"—the amount of food calories you should consume to stay at your current weight.
The Science of Weight Management
The fundamental principle of weight management is the energy balance equation:
- Weight Loss: Consuming fewer calories than your TDEE (Caloric Deficit).
- Weight Gain: Consuming more calories than your TDEE (Caloric Surplus).
- Maintenance: Consuming calories equal to your TDEE.
Macro-nutrients and Caloric Density
| Nutrient | Calories per Gram | Function |
|---|---|---|
| Protein | 4 kcal | Muscle repair and enzyme production |
| Carbohydrates | 4 kcal | Primary energy source for the brain and muscles |
| Fats | 9 kcal | Hormone production and vitamin absorption |
Example Calculation
Consider a 30-year-old male, 180cm tall, weighing 85kg with a "Moderately Active" lifestyle:
1. BMR = (10 × 85) + (6.25 × 180) – (5 × 30) + 5 = 1,830 calories.
2. TDEE = 1,830 × 1.55 = 2,836 calories.
To lose weight safely, he might target 2,336 calories (a 500-calorie deficit).