Enter the number of protons in the element and the number of neutrons in the element into the Element Mass Calculator. The calculator will evaluate and display the Element Mass. 

Element Mass Formula

The following formula is used to calculate the Element Mass. 

Me = #N + #P

  • Where Me is the Element Mass (amu)
  • #P is the number of protons in the element 
  • #N is the number of neutrons in the element 

How to Calculate Element Mass?

The following example problems outline how to calculate Element Mass.

Example Problem #1:

  1. First, determine the number of protons in the element. 
    • The number of protons in the element is given as: 8.
  2. Next, determine the number of neutrons in the element. 
    • The number of neutrons in the element is provided as: 8.
  3. Finally, calculate the Element Mass using the equation above: 

Me = #N + #P

The values given above are inserted into the equation below and the solution is calculated:

Me = 8 + 8 = 16 (amu)


Example Problem #2: 

For this problem, the variables needed are provided below:

number of protons in the element = 9

number of neutrons in the element = 10

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer. 

Me = #N + #P = ?