What is TDEE?
Total Daily Energy Expenditure (TDEE) is the total number of calories your body burns in a day, including rest, exercise, and daily activities. TDEE is a function of the BMR, TEF, EAT and NEAT.
How the Calculator Works
Using your Basal Metabolic Rate (BMR) and multiplying it by an activity factor, the calculator provides your daily calorie needs for maintenance. The activity factors to multiply with BMR to arrive at the estimated TDEE are as follows:
- TEF: - This is the Thermic Effect of feeding. You spend energy when feeding, digesting and absorbing food and this is what is known as TEF. In fact, some foods like proteins spend more energy to disgest than others like fatty foods.
- EAT: - This is known as Exercise Activity Thermogesis. It is the energy spent when doing active exercise like unplanned physical work, Gym, running, playing, etc.
- NEAT: - This stands for Non-Exercise Activity Thermogenesis. Even when not exercising actively, men and women spend energy unplanned activities like fidgeting, walking from here to there, tapping, etc. This is also energy spent and is considered when calculating TDEE.
To easier and better calculate TDEE, three main formulae are used:
- Katch-McArdle.
- Mifflin-St. Jeor.
- Harris-Benedict.
Let us dive into more details about these formulae:
1. Harris–Benedict Equation (Revised 1984)
? This is One of the oldest and most widely used formulas. It often slightly overestimates calories, especially for sedentary people.
As mentioned above, males and females (men and women) have different TDEEs and this is factored in in this Harris–Benedict Equation.
- Men
-
BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) − (5.677 × age)
- Women
-
BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) − (4.330 × age)
- Then
-
TDEE = BMR × Activity Factor
2. Mifflin–St Jeor Equation (1990)
? Mifflin–St Jeor Equation of 1990 is Considered more accurate for modern populations. This is the formula most dietitians and calculators use today. However, C4Calc TDEE calculator uses the three formulaer so you also see he difference and also understand how far TDEE Calculation has come along.
- Male
-
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Female
-
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
- Then
-
TDEE = BMR × Activity Factor
3. Katch–McArdle Equation (uses lean body mass)
? The Katch–McArdle Equation is best used when you know body fat % because it uses lean body mass (LBM) - see Lean Body Mass Calculator, making it useful for athletes or those with atypical body composition.
- Formula
-
BMR = 370 + (21.6 × Lean Body Mass in kg)
- Where
-
Lean Body Mass (LBM) = weight in kg × (1 − body fat %)
- Then
-
TDEE = BMR × Activity Factor
Note: Activity Factor is a multiplier that reflects daily activity (e.g., 1.2 = sedentary, 1.55 = moderately active). Choose the formula based on the data you have: use Katch–McArdle if you know body-fat %, otherwise Mifflin–St Jeor is a solid default.
Why Knowing TDEE is important
- Weight loss — to lose weight, you need to consume fewer calories than your TDEE.
- Muscle gain — eat more calories than your TDEE in order to gain Muscle or to Gain weight.
- Maintenance — you must match intake to TDEE to maintain weight of this is your goal.
A TDEE calculator is therefore important in knowing the direction to take to either reduce or gain weight depending on your goal. However, it doesn't tell you if you are within the desired range of weight. For this, you need to use a BMI calculator.
Final Thoughts
The TDEE Calculator is a cornerstone tool for fitness planning.
Use it alongside C4 Calc’s
BMR Calculator,
Body Fat Calculator,
Lean Body Mass Calculator,
Calorie Calculator,
Protein Calculator,
Macro Calculator, and
Calories Burned Calculator
for complete and accurate results tailored to your goals.
For extra context on your health and body composition, you can also explore our BMI Calculator and
Healthy Weight Calculator.
Together, these tools give you a full picture of your energy needs, fitness progress, and ideal targets.
