Use this webpage to estimate the potential energy savings for pump motors in your water or wastewater plant. Enter the pump horsepower in the calculator, and locate the approximate hours per year the pump runs to estimate the potential payback for adding a VFD. This should provide a rough estimate of whether a VFD project makes sense foryour pumping system.
Pump Horsepower (HP)
VFD Cost Per Horsepower ($/HP)
Motor Efficiency (%)
Assumed kWh Cost ($/kWh)
Assumed VFD Saving (%)

*VFD Cost Per Horsepower ($/HP): $500 per horsepower is an average estimate for installed VFD costs, including wiring upgrades, programming, and other costs. If you have actual project costs, divide by the total installed motor horsepower and enter that value here.

*Motor Efficiency: If your motor efficiency is unknown, enter a value from the Table below based on your motor rated horsepower. Otherwise, enter the motor’s rated efficiency from the manufacturer’s data or motor nameplate.

*Assumed kWh Cost ($): The IL State average in 2021 was about $0.11/kWh. Enter your local cost if known.

*Assumed VFD Saving (%): 20% is an industry average savings for VFDs on pumps. Adjust if you have a better estimate.

VFD Cost ($)

Open Hours per Year (hr) kWh Reduction (kWh) Anual Cost Saving ($) Simple Payback (yr)