Formula
CR=(swept+clearance)/clearance.
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Geometric volume ratio only, not cranking pressure, dynamic compression ratio or knock prediction.
Example Calculation
Example inputs
- Swept volume per cylinder: 500 cm³
- Clearance volume: 50 cm³
Swept volume per cylinder = 500; Clearance volume = 50. Primary result: 11.
Frequently asked questions
How do I use this calculator?
Enter swept volume per cylinder, clearance volume. The result updates automatically. Use Reset to restore the example values.
What method does it use?
CR=(swept+clearance)/clearance.. Geometric volume ratio only, not cranking pressure, dynamic compression ratio or knock prediction.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.