To know how many calories you burn, you need to calculate your Total Daily Energy Expenditure (TDEE), which includes the calories your body uses for basic functions plus those burned through physical activity.
Steps to Calculate Calories Burned
1. Calculate Basal Metabolic Rate (BMR):
BMR is the number of calories your body needs to maintain vital functions like
breathing, heartbeat, and organ function at rest. It typically accounts for
40-70% of your total calorie burn. Common equations to estimate BMR include:
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Mifflin-St Jeor Equation:
For men: (9.65×weight in kg)+(573×height in m)−(5.08×age)+260(9.65\times \text{weight in kg})+(573\times \text{height in m})-(5.08\times \text{age})+260(9.65×weight in kg)+(573×height in m)−(5.08×age)+260
For women: (7.38×weight in kg)+(607×height in m)−(2.31×age)+43(7.38\times \text{weight in kg})+(607\times \text{height in m})-(2.31\times \text{age})+43(7.38×weight in kg)+(607×height in m)−(2.31×age)+43 -
Harris-Benedict Equation: Another widely used formula that estimates BMR based on weight, height, age, and sex.
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Katch-McArdle Formula: Uses lean body mass for more accuracy if body fat percentage is known
2. Adjust for Activity Level:
Multiply your BMR by an activity factor to account for calories burned through
daily activities and exercise:
- Sedentary (little or no exercise): 1.2
- Lightly active (light exercise 1-3 days/week): 1.37
- Moderately active (moderate exercise 3-5 days/week): 1.55
- Very active (hard exercise 6-7 days/week): 1.725
- Extra active (very hard exercise or physical job): 1.9
3. Calculate Total Daily Energy Expenditure (TDEE):
TDEE = BMR × Activity Level This gives an estimate of how many calories you
burn in a day including all activities
Other Methods to Measure Calorie Burn
- Heart Rate Monitors: Track your heart rate during exercise to estimate calorie burn more accurately since heart rate correlates with effort
- Activity Trackers and Apps: Provide estimates based on movement data but can vary in accuracy
- Metabolic Testing: Using specialized equipment to measure oxygen consumption and carbon dioxide production during activity can precisely determine calorie expenditure, but this is usually done in lab settings
Summary
To know how many calories you burn:
- Calculate your BMR using a formula based on your age, sex, weight, and height.
- Multiply your BMR by your activity level to get your TDEE.
- Use heart rate monitors or activity trackers for more personalized estimates during exercise.
This approach helps you understand your energy needs for weight management or fitness goals
