Transformer Efficiency Calculator
Enter measured real output and input power using the same unit and the same time-period boundary.
A QUICK WALKTHROUGH
How to use this tool
- Measure real power at the transformer output and input.
- Use the same power unit and matching measurement period for both values.
- Calculate output power divided by input power as a percentage.
Formula
Efficiency (%) = measured real output power ÷ measured real input power × 100%. Both measurements must use the same unit and cover the same time interval.
Scope and limits
This is a ratio of manually entered measurements. It does not represent a nameplate guarantee, validate instruments, or account for measurement uncertainty or operating conditions.
GOOD TO KNOW
Common questions
Can I compare readings from different periods?
No. Use the same time-period boundary so the measurements describe matching operation.
Does this report rated efficiency?
No. It calculates a ratio from your measurements and is not a nameplate guarantee.