Enter the power (watts) and the time (seconds) into the calculator to determine the Energy. 

Energy Formula

The following equation is used to calculate the Energy. 

E = P*T


  • Where E is the Energy (Joules)
  • P is the power (watts) 
  • T is the time (seconds) 

To convert power to energy, multiply the power in watts by the time in seconds.

How to Calculate Energy?

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

Example Problem #1:

  1. First, determine the power (watts). In this example, the power (watts) is measured to be 85.
  2. Next, determine the time (seconds). For this problem, the time (seconds) is calculated to be 9.
  3. Finally, calculate the Energy using the formula above: 

E = P*T

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

E = 85*9 = 765 (Joules)

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: 

power (watts) = 2

time (seconds) = 4

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

E = 2*4 = 8 (Joules)