Enter the volume of the water change (L) and the volume of the tank (L) into the Water Change Calculator. The calculator will evaluate the Water Change. 

Water Change Formula

The following two example problems outline the steps and information needed to calculate the Water Change.

WC = WCV / WT * 100

Variables:

  • WC is the Water Change (%)
  • WCV is the volume of the water change (L) 
  • WT is the volume of the tank (L) 

How to Calculate Water Change?

The following steps outline how to calculate the Water Change.


  1. First, determine the volume of the water change (L). 
  2. Next, determine the volume of the tank (L). 
  3. Next, gather the formula from above = WC = WCV / WT * 100.
  4. Finally, calculate the Water Change.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

volume of the water change (L) = 4

volume of the tank (L) = 10

WC = WCV / WT * 100 = ?