Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE) Calculator
Your Results:
Basal Metabolic Rate (BMR): — kcal/day
Total Daily Energy Expenditure (TDEE): — kcal/day
Understanding Your Basal Metabolic Rate (BMR) and Total Daily Energy Expenditure (TDEE)
Your Basal Metabolic Rate (BMR) represents the minimum number of calories your body needs to perform essential life-sustaining functions while at rest. Think of it as the energy required to keep your heart beating, lungs breathing, brain functioning, and body temperature regulated. This is the energy your body burns even if you were to do absolutely nothing all day.
Several factors influence your BMR, including your age, gender, weight, and height. Generally, individuals with more lean muscle mass have a higher BMR because muscle tissue burns more calories at rest than fat tissue.
The Mifflin-St Jeor Equation
This calculator uses the Mifflin-St Jeor equation, which is widely considered one of the most accurate formulas for estimating BMR:
- For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
Once your BMR is calculated, you can estimate your Total Daily Energy Expenditure (TDEE). TDEE accounts for the calories you burn through all activities, including your BMR, the thermic effect of food (energy used for digestion), and the energy expended during physical activity.
Calculating Your Total Daily Energy Expenditure (TDEE)
To calculate your TDEE, your BMR is multiplied by an activity factor that corresponds to your lifestyle:
- Sedentary: BMR × 1.2 (little or no exercise)
- Lightly active: BMR × 1.375 (light exercise/sports 1-3 days/week)
- Moderately active: BMR × 1.55 (moderate exercise/sports 3-5 days/week)
- Very active: BMR × 1.725 (hard exercise/sports 6-7 days a week)
- Extra active: BMR × 1.9 (very hard exercise/sports & physical job)
Understanding your BMR and TDEE is crucial for managing your weight. If your calorie intake is consistently higher than your TDEE, you will likely gain weight. Conversely, if you consume fewer calories than your TDEE, you will likely lose weight. For maintaining weight, your calorie intake should closely match your TDEE.
Example Calculation:
Let's consider Sarah, a 32-year-old woman who weighs 65 kg, is 168 cm tall, and engages in moderate exercise 4 days a week.
- Gender: Female
- Weight: 65 kg
- Height: 168 cm
- Age: 32 years
- Activity Level: Moderately active (1.55)
BMR Calculation (Mifflin-St Jeor for Women):
BMR = (10 × 65) + (6.25 × 168) – (5 × 32) – 161
BMR = 650 + 1050 – 160 – 161
BMR = 1379 kcal/day
TDEE Calculation:
TDEE = BMR × Activity Factor
TDEE = 1379 × 1.55
TDEE = 2137.45 kcal/day
So, Sarah needs approximately 1379 kcal to maintain her basic bodily functions at rest and around 2137 kcal per day to maintain her current weight, considering her activity level.