Thermal Efficiency Calculator

Find a heat engine's thermal efficiency.

Thermal efficiency (%) 40

Formula: η = W_out ÷ Q_in × 100

Step-by-step with your numbers:

1. Values used:

2. Work output = 400 J

3. Heat input = 1,000 J

5. Thermal efficiency = 40%

Did we solve your problem today?

Thermal efficiency is the fraction of heat input converted to useful work.

The math behind it

η = W_out ÷ Q_in. The rest is rejected as waste heat.

400 J work from 1000 J heat → 40%.

Can it reach 100%?

No — the Carnot limit caps efficiency below 100%.