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EER to COP Conversion

EER=3.412×COP\mathrm{EER} = 3.412 \times \mathrm{COP}

Units aren’t used in this calculation: every value is a plain number.

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Worked example: COP 3.0 → EER 10.236. Press Try an example to run it live, then adjust anything.

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Where EER to COP Conversion fits

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See also

Energy Efficiency Ratio (EER): Both use energy efficiency ratio.Coefficient of Performance (COP): Both use coefficient of performance.Refrigeration COP from Enthalpies: Both use coefficient of performance.
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EER to COP Conversion explained

0COPEER

The two numbers describe identical hardware; only the bookkeeping differs. COP is watts out per watt in: clean, dimensionless, and what the rest of the world quotes. EER divides BTU/hr out by watts in, which leaves the conversion factor 3,600/1,055.06 = 3.412 stranded inside the ratio. Multiply COP by 3.412 to get EER, divide to go back.

Useful landmarks: a minimum-efficiency US split system at EER 11 is COP 3.22; a good variable-speed machine at EER 14 is COP 4.10; a water-cooled chiller at 0.5 kW/ton corresponds to EER 24 and COP 7.0. The trap is arithmetic drift: 3.412 is often rounded to 3.41 or even 3.4, which shifts a COP-to-EER conversion by up to a third of a point, enough to move a piece of equipment across a rebate threshold. Worked example: COP 3.0 × 3.412 = EER 10.24; going the other way, a SEER-13 nameplate implies roughly COP 3.81 at its rating point.

EER to COP Conversion formula

EER=3.412×COP\mathrm{EER} = 3.412 \times \mathrm{COP}
Where
  • EER\mathrm{EER}= Energy efficiency ratio (BTU/(h·W))
  • COP\mathrm{COP}= Coefficient of performance
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Refrigeration capacity and efficiency

6 formulasTons, COP, EER and kW per ton — the four ways the trade states the same chiller performance, and how to convert between them.

Revised 31 October 2026
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formula.expert. (2026, October 31). EER to COP Conversion Formula & Calculator. https://formula.expert/solvers/eer-cop-conversion

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