Compression Ratio Calculator
Calculate static compression ratio from swept and total clearance volume.
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What this tool does
Calculate static compression ratio from swept and total clearance volume. Clearance includes chamber, gasket, deck and piston volume; dynamic compression is not calculated.
How to use the Compression Ratio Calculator
- Enter or select swept volume per cylinder (cc).
- Enter or select total clearance volume (cc).
- Read the calculated result; change any measurement to compare alternatives.
Formula
compression ratio=(swept+clearance)/clearance
- swept
- Swept volume per cylinder (cc)
- clearance
- Total clearance volume (cc)
Clearance includes chamber, gasket, deck and piston volume; dynamic compression is not calculated.
Worked example
For compression ratio calculator, the following measurements illustrate the exact method: Swept volume per cylinder (cc): 500; Total clearance volume (cc): 55.
Inputs
- Swept volume per cylinder (cc)500
- Total clearance volume (cc)55
Result
- Compression ratio10.09
Results explained
- Compression ratio
- Compression ratio from the formula above. Clearance includes chamber, gasket, deck and piston volume; dynamic compression is not calculated.
Frequently asked questions
compression ratio=(swept+clearance)/clearance
Use the tire sidewall markings, actual vehicle specifications or recorded fuel/price values required by the inputs. Do not mix US gallons and imperial gallons.
Clearance includes chamber, gasket, deck and piston volume; dynamic compression is not calculated.
Yes. Change the relevant size, price or efficiency while keeping the other inputs constant. Results update immediately.
No. Check manufacturer fitment, load and speed ratings, clearance and local requirements with a qualified technician.