Enter the total grams of protein (g) into the calculator to determine the Energy from Protein. 

Protein to Energy Calculator

Enter any 1 value to calculate the missing variable

Energy from Protein Formula

The following equation is used to calculate the Energy from Protein. 

E = P*4

Variables:

  • Where E is the Energy from Protein (kcal)
  • P is the total grams of protein (g) 

To calculate the energy from protein, multiply the protein weight in grams by 4.

Protein (g) to Kilocalories (kcal) Conversion Table (4 kcal per gram)
Protein (g) Energy (kcal)
14
28
312
520
728
1040
1248
1560
2080
25100
30120
35140
40160
45180
50200
60240
75300
80320
90360
100400
*Uses Atwater factor for protein: 1 g protein = 4 kcal (≈ 16.736 kJ). Default energy unit in calculator: kcal.

How to Calculate Energy from Protein?

The following two example problems outline the steps and information needed in order to calculate the Energy from Protein.

Example Problem #1:

  1. First, determine the total grams of protein (g). In this example, the total grams of protein (g) is measured to be 45.
  2. Finally, calculate the Energy from Protein using the formula above: 

E = P*4 = (kcal)

Inserting the values from above and solving the equation with the imputed values gives: 

E = 45*4 = 180 kcal


Example Problem #2: 

Using the same process as example problem 1, we first define the needed variables outlined by the formula. In this case, the values are provide as: 

total grams of protein (g) = 40

Entering these values into the formula or calculator above gives us: 

E = 40*4 = 160 (kcal)