What this calculator does
Carnot efficiency works out maximum possible efficiency of a heat engine between two temperatures. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulaη = 1 − Tc/Th (temperatures in kelvin)
The inputs explained
| Field | What to enter |
|---|---|
| Hot reservoir temperature (°C) | A number, measured in °C. Starts at 500. |
| Cold reservoir temperature (°C) | A number, measured in °C. Starts at 30. |
| Heat input per cycle (J) | A number, measured in J. Starts at 1000. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with hot reservoir temperature
Every other input is held at the calculator’s starting values while hot reservoir temperature varies. Select any row to load that scenario into the calculator.