Carnot Efficiency Calculator

Carnot Efficiency Formula

Worked Example

An engine between 600 K and 300 K:

1. η = 1 − TL/TH (absolute temperatures)
2. = 1 − 300 K ÷ 600 K = 0.5
3. = 50 %

COP of a Carnot heat pump TH/(TH − TL): 2

More Thermodynamics Calculators

• Otto Cycle Calculator

  η = 1 − 1/r^(γ−1)

  r compression ratio, γ = cp/cv

  Example: r = 8, γ = 1.4, intake 300 K and 100 kPa, peak 2000 K: Air-standard efficiency η = 56.4725 %.

  Open the otto cycle calculator →

• Brayton Cycle Calculator

  η = 1 − 1/rp^((γ−1)/γ)

  rp pressure ratio; optimum rp = (T₃/T₁)^(γ/2(γ−1)) for maximum work

  Example: rp = 10, T₁ = 300 K, T₃ = 1200 K, ideal compressor and turbine: Thermal efficiency η = 48.2053 %.

  Open the brayton cycle calculator →

• Diesel Cycle Calculator

  η = 1 − [1/r^(γ−1)] × (ρ^γ − 1)/[γ(ρ − 1)]

  r compression ratio, ρ = V₃/V₂ cut-off ratio

  Example: r = 18, cut-off ratio 2, γ = 1.4, intake 300 K and 100 kPa: Air-standard efficiency η = 63.1578 %.

  Open the diesel cycle calculator →

• Polytropic Process Calculator

  W = (p₁V₁ − p₂V₂)/(n − 1), Q = W(γ − n)/(γ − 1)

  pVⁿ = constant; n = 1 isothermal W = p₁V₁ ln(V₂/V₁)

  Example: Air compressed from 100 kPa, 0.1 m³, 300 K to 800 kPa with n = 1.3: Work done by the gas W = -20.5289 kJ.

  Open the polytropic process calculator →

Frequently asked questions

Sources

Last reviewed: 2026-10-15. Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.