What COP measures
The coefficient of performance (COP) describes how efficiently a refrigerator, air conditioner, or heat pump moves heat compared to the work (usually electrical energy) it consumes. A higher COP means better efficiency — unlike a simple heat engine, COP values are often greater than 1.
The formula
COP = Q / W, where Q is the heat transferred (removed from a cold space for cooling, or delivered to a warm space for heating) and W is the work input required to do it. This calculator reports COP directly from your heat and work values; the interpretation (cooling vs heating) depends on which system type you select.
This calculator is for general thermodynamics education and appliance-efficiency reference.
Last reviewed August 2026