Work out cop and eer instantly with clear inputs, formula shown and shareable results.
EER is cooling output in BTU per hour divided by electrical input in watts, measured at a single rating condition. COP is the same ratio in consistent units, so dividing EER by 3.412 converts between them. Chiller plant engineers prefer kW per ton, which is simply 12 divided by EER.
Efficiency ratios
EER = BTU/h / W; COP = EER / 3.412; kW/ton = 12 / EER
EER = BTU/h / W; COP = EER / 3.412; kW/ton = 12 / EER. EER is cooling output in BTU per hour divided by electrical input in watts, measured at a single rating condition.
EER is a single-point rating at 95 °F outdoor air. SEER averages performance across a simulated cooling season, so it is usually a higher number for the same machine.
This calculator takes 2 inputs: Cooling capacity, Electrical power input. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.