Fundamentals
Electrical Efficiency Calculator
Calculate a transparent input/output power ratio.
02 / Result
Electrical efficiency estimate
η = Pout / Pin · η% = 100 × η · Ploss = Pin − Pout
Calculated results will appear here.
Method and boundaries
η = Pout / Pin; loss = Pin − Pout. The Pout ≤ Pin domain is specific to this calculator and does not judge all real devices.
FAQ
What does this calculator compute?
Efficiency is output power divided by input power. Loss is input power minus output power.
What domain does it enforce?
This calculator requires output power to be less than or equal to input power. That limit belongs to this tool and is not a judgment of every real device.
What should the powers represent?
Enter both powers on the same basis and in the same unit. The tool does not convert between electrical input and shaft output for you.
Source records
Determining Electric Motor Load and Efficiency (SRC-040)
Institution: U.S. Department of Energy
Section: General efficiency ratio Pout/Pin. Motor-specific measurement methods are not used.
URL on the calculation record: https://www.energy.gov/sites/default/files/2014/04/f15/10097517.pdf
Verification date: 2026-10-12
Status: review-required