Efficiency Calculator

Power in, power out, and what went missing.

Measure input and output power at the same time if you can. Everything is worked out in your browser. Nothing is saved or sent anywhere.

1. Power

2. Results

How it was worked out

    What this does and doesn't tell you

    • Most converters are least efficient at very light loads.
    • The lost power turns into heat, so it needs ventilation.
    • 240V AC mains can kill. In Australia, work on household mains wiring must be carried out by a licensed electrician. Low-voltage DC systems can still deliver very high current.
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