Otto Cycle Calculator
Calculate Otto cycle thermal efficiency and state-point temperatures and pressures from compression ratio
Otto Cycle Calculator
η = 1 − 1/r^(γ-1) · Ideal air-standard Otto cycle
Typical: 8–12
Air: 1.4
Cycle Efficiency
56.47%
η = 1 − 1/8.0^(1.40−1) = 0.5647
State Points
| State | T (K) | P (kPa) |
|---|---|---|
| 1 (BDC, start) | 300.0 | 100.0 |
| 2 (TDC, compressed) | 689.2 | 1837.9 |
| 3 (TDC, combustion) | 1803.7 | 4810.0 |
| 4 (BDC, expanded) | 785.1 | 261.7 |
Energy Summary
q_in
800.0 kJ/kg
W_net
451.8 kJ/kg
q_out
348.2 kJ/kg
How to Use This Calculator
Enter your input values
Fill in all required input fields for the Otto Cycle Calculator. Most fields include unit selectors so you can work in your preferred unit system.
Review your inputs
Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors.
Read the results
The Otto Cycle Calculator instantly computes the output and displays results with units. All calculations happen in your browser — no loading time and no data sent to a server.
Formula Reference
Otto Cycle Calculator Formula
See calculator inputs for the governing equation
Variables: All variables and their units are labeled in the calculator interface above.
When to Use This Calculator
- •Use the Otto Cycle Calculator when solving homework or exam problems that require quick numerical verification of your hand calculations.
- •Use it during the design phase to rapidly iterate on parameters before running detailed finite element simulations.
- •Use it when reviewing a colleague's calculation or checking a vendor's data sheet for plausibility.
- •Use it to generate reference data for a technical report or presentation without manual computation.
Related Calculators
Ideal Gas Law Calculator
Solve for P, V, n, or T using PV = nRT with unit conversions for pressure, volume, and temperature
Isentropic Process Calculator
Calculate isentropic process relations between states using P, V, T and the specific heat ratio γ
Carnot Efficiency Calculator
Calculate Carnot cycle efficiency, net work, and required temperatures for a given efficiency
Diesel Cycle Calculator
Calculate Diesel cycle thermal efficiency from compression ratio, cutoff ratio, and specific heat ratio
Rankine Cycle Calculator
Calculate Rankine cycle efficiency, turbine work, pump work, and heat input from state-point enthalpies
Heat Engine Calculator
Solve for Q_in, Q_out, W_net, or efficiency given any two of the four heat engine quantities