ONE FORMULA, ONE ANSWER
Carnot Efficiency Limit Calculator
Check the theoretical efficiency limit for a heat engine between two reservoirs. Choose input units and calculate one value within the stated conditions.
Inputs
Calculations run in this browser. Scientific notation such as 1.2e-3 is supported. Do not group thousands.
Result
Carnot efficiency limit η_C
Enter values and select Calculate.
η_C = 1 − T_c / T_h
Assumptions
Use T_h>T_c>0 K. This is the reversible heat-engine upper bound between two reservoirs, not the efficiency of a real device. Celsius temperatures must not be divided directly.
Displayed values are floating-point approximations. Measurement uncertainty and design safety factors are not calculated.
Formula references and credits
NaNa Lab created the code, descriptions, icons and preview images. Text, figures and code from the linked references have not been reproduced.
Physical constants: NIST / CODATA 2022. The values of μ₀ and ε₀ are measured recommendations, not exact defining constants. Values and precision notes are in the source record.
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