Motor Operating-Cost Calculator — Turn Motor Load Into Annual Cost
Estimate how much electricity a motor consumes at its actual operating load and translate that usage into annual, monthly and hourly operating cost.
Motor operating assumptions
How motor operating cost is calculated
Useful shaft output is estimated from rated motor power and average load percentage. That output is divided by efficiency to estimate electrical input power. Energy consumption is then input power multiplied by operating hours.
Why efficiency matters
Two motors delivering the same useful output can consume different electrical power when their efficiencies differ. Even a modest efficiency difference can accumulate over thousands of operating hours.
Why load percentage is important
A motor rarely operates at rated output continuously in many applications. Modeling the actual average loading produces a more useful operating-cost estimate than assuming 100% load for every hour.
Worked example
A 30 kW motor operating at 70% average load and 92% efficiency has an estimated electrical input of about 22.83 kW. At 4,000 hours per year, this is roughly 91.3 MWh/year.
What is excluded
Demand charges, reactive-power charges, tariff blocks, standby charges, variable speed drive losses and changing load profiles are not automatically modeled.
Decision use
The result is useful for early energy budgeting, motor replacement studies and estimating the running-cost impact of changing operating schedules.
Frequently asked questions
Can I use actual measured average load?
Yes. A realistic operating-load estimate is preferable to automatically assuming full load.
Is the electricity price live?
No. Enter the tariff you want to analyze.
Does this include motor starting energy?
No. This is an operating-cost model for normal running conditions.