Enter the total distance in parsecs into the calculator to determine the distance modulus.

Distance Modulus Formula

The following formula is used to calculate a distance modulus.

m-M = 5*log(r/10)
  • Where m-M is the distance modulus
  • r is total absolute distance (parsecs)

To calculate a distance modulus, take the log of the absolute distance over 10, then multiply by 5.

What is a distance modulus?

Definition:

A distance modulus is defined as the total distance to an object with respect to its apparent magnitude and absolute magnitude.

Distance modulus is used to understand the distance of extragalactic objects that are extremely far away in relative terms.

How to calculate distance modulus?

Example problem:

The following example outlines how to calculate a distance modulus.

First, determine the distance between objects in parsecs. For this example, the objects are 25 parsecs apart.

Next, use the formula above to calculate the distance modulus.

m-M = 5*log(r/10)

m-M = 5*log(25/10)

m-M = 1.9897