Online Calorie Calculator
Calculate your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE).
How This Calorie Calculator Works
Understanding your daily caloric needs is the foundation of any successful fitness journey. This calculator uses the Mifflin-St. Jeor Equation, which is currently considered the most accurate formula for estimating Basal Metabolic Rate (BMR) for the general population.
The Science of BMR and TDEE
BMR (Basal Metabolic Rate): This is the amount of energy your body burns just to keep you alive while at rest—powering your heart, lungs, and brain. It accounts for about 60-75% of your total daily burn.
TDEE (Total Daily Energy Expenditure): This is the total number of calories you burn per day once physical activity is included. We calculate this by multiplying your BMR by an activity factor (PAL):
- Sedentary: BMR x 1.2
- Lightly Active: BMR x 1.375
- Moderately Active: BMR x 1.55
- Very Active: BMR x 1.725
- Extra Active: BMR x 1.9
Example Calculation
If you are a 30-year-old male, weighing 80kg, and standing 180cm tall, your BMR would be roughly 1,790 calories. If you exercise 3 times a week (Moderately Active), your TDEE would jump to approximately 2,775 calories. To lose roughly 0.5kg (1 lb) per week, you would aim for a "Weight Loss" target of 2,275 calories.
How to Use Your Results
Once you have your maintenance calories (TDEE), you can adjust your intake based on your goals. For weight loss, a deficit of 500 calories per day is often recommended. For muscle gain, a surplus of 250 to 500 calories, combined with strength training, is the standard approach. Remember that these are estimates, and factors like body composition (muscle mass vs. fat mass) can shift the numbers.