Enter the radius of the event horizon (km) into the Black Hole Mass Calculator. The calculator will evaluate and display the Black Hole Mass. 

Black Hole Mass Formula

The following formula is used to calculate the Black Hole Mass. 

BHM = R / 3

  • Where BHM is the Black Hole Mass (solar mass units)
  • R is the radius of the event horizon (km) 

How to Calculate Black Hole Mass?

The following example problems outline how to calculate Black Hole Mass.

Example Problem #1:

  1. First, determine the radius of the event horizon (km). 
    • The radius of the event horizon (km) is given as: 13,000,000.
  2. Finally, calculate the Black Hole Mass using the equation above: 

BHM = R / 3

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

BHM = 13,000,000 / 3 = 4,333,333.33 (solar mass units)

Example Problem #2: 

For this problem, the variables needed are provided below:

radius of the event horizon (km) = 10,000,000

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

BHM = R / 3 = ?