Enter the number of protons and the number of electrons into the calculator to determine the Atomic Charge. 

Atomic Charge Formula

The following formula is used to calculate the Atomic Charge. 

AC = P - E
  • Where AC is the Atomic Charge (eV)
  • P is the number of protons 
  • E is the number of electrons 

To calculate an atomic charge, simply subtract the number of electrons from the number of protons.

How to Calculate Atomic Charge?

The following two example problems outline how to calculate the Atomic Charge.

Example Problem #1:

  1. First, determine the number of protons. In this example, the number of protons is given as 50.
  2. Next, determine the number of electrons. For this problem, the number of electrons is given as 49.
  3. Finally, calculate the Atomic Charge using the equation above: 

AC = P – E

Inserting the values from above and solving the equation: 

AC = 50 – 49 = 1 (eV)


Example Problem #2: 

Using the same process as above, first define the variables required by the formula. In this case, these values are provided as the following:

number of protons = 15

number of electrons = 17

Entering these values gives:

AC = 15 – 17 = -2 (eV)