Enter the original water level (gallons) and the final water level (gallons) into the Calculator. The calculator will evaluate the Evaporation Loss. 

Evaporation Loss Formula



  • EL is the Evaporation Loss (gallons)
  • OWV is the original water level (gallons)
  • FWV is the final water level (gallons)

To calculate Evaporation Loss, subtract the final water level after evaporation from the original water level.

How to Calculate Evaporation Loss?

The following steps outline how to calculate the Evaporation Loss.

  1. First, determine the original water level (gallons). 
  2. Next, determine the final water level (gallons). 
  3. Next, gather the formula from above = EL = OWV – FWV.
  4. Finally, calculate the Evaporation Loss.
  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.

original water level (gallons) = 4300

final water level (gallons) = 3000

Frequently Asked Questions

What factors affect evaporation loss in water bodies?

Several factors can affect evaporation loss, including temperature, humidity, wind speed, and the surface area of the water body. Higher temperatures and wind speeds increase evaporation rates, while higher humidity levels decrease them.

Can evaporation loss be prevented or reduced?

While it’s impossible to completely prevent evaporation loss, measures such as covering pools when not in use, reducing the surface area of water exposed to air, and using windbreaks can significantly reduce evaporation rates.

Why is it important to calculate evaporation loss in water management?

Calculating evaporation loss is crucial for effective water management, especially in areas with limited water resources. It helps in planning water storage and distribution, ensuring there is enough water for various needs such as agriculture, drinking, and industrial processes.

How accurate are evaporation loss calculations?

The accuracy of evaporation loss calculations can vary based on the method used and the accuracy of the input data. Using detailed climate data and precise measurements of water levels can improve the accuracy of these calculations.