Carnot Efficiency Calculator

Calculate the maximum theoretical efficiency of heat engines

Temperature Unit:

Hot Reservoir Temperature (K):

Cold Reservoir Temperature (K):

Heat Input (J or kJ): (optional)

About Carnot Efficiency

The Carnot efficiency represents the maximum possible efficiency for any heat engine operating between two thermal reservoirs. It is a fundamental limit set by the Second Law of Thermodynamics.

Key Formulas:

η = 1 - Tc/Th (Carnot efficiency)
COPhp = Th/(Th-Tc) (heat pump)
COPref = Tc/(Th-Tc) (refrigerator)
W = Qh - Qc (work = heat in - heat out)

Important Notes:

Real engines always have lower efficiency than Carnot
Higher Th or lower Tc increases efficiency
COP > 1 is possible for heat pumps (not violating thermodynamics)