One cylinder's volume, broken into its parts
Every cylinder has three volumes worth knowing: how much it sweeps between top and bottom dead centre, how much is left at the top, and the two added together. Static compression ratio ties all three together.
Building compression from the four real volumes rather than an assumed clearance? The full compression ratio calculator itemises chamber, gasket, deck and piston separately.
Getting a number you can act on
- 01Enter bore and stroke
These set the swept volume — the space the piston physically travels through, which is the same number displacement is built from.
- 02Enter the static compression ratio
Rather than itemising chamber, gasket, deck and piston separately, this works backward from a target ratio to the clearance volume it implies.
- 03Read swept, clearance and total together
Swept is fixed by geometry alone. Clearance is what a given ratio requires. Total is simply the two added — the full volume at bottom dead centre.
What the calculator is actually doing
Nothing here is proprietary. If you would rather check it by hand, or explain it to someone at a counter, these are the same expressions the tool evaluates.
swept (cc) = π ÷ 4 × bore² × stroke × 16.387The same calculation the displacement calculator uses, for one cylinder.
clearance (cc) = swept ÷ (compression ratio − 1)Rearranged from the standard compression ratio formula: CR = (swept + clearance) ÷ clearance.
Why this is a shortcut, not a replacement
The full compression ratio calculator itemises clearance volume into four separate physical contributors — chamber, head gasket, deck clearance and piston dome or dish — because each is measured or specified independently on a real engine.
This tool skips that breakdown and works directly from a target ratio to a single clearance figure. That is the right tool when you want a quick number — how much total volume a cylinder holds at bottom dead centre for a given bore, stroke and compression target — without needing to specify every individual component that adds up to it.
When the individual components genuinely matter, such as machining a deck or selecting a gasket thickness to hit a target ratio, the full compression ratio calculator is the one to use instead.
Cylinder Volume Calculator FAQ
How do I calculate cylinder volume?+
Swept volume comes from bore, stroke and the standard displacement formula. Clearance volume follows from a target compression ratio: swept ÷ (ratio − 1). Add them together for total volume at bottom dead centre.
What is the difference between swept and total cylinder volume?+
Swept volume is only what the piston travels through between top and bottom dead centre. Total volume adds the clearance space still present at top dead centre — swept plus clearance.
How much clearance volume does a 10:1 compression ratio need?+
Clearance volume equals swept volume divided by (ratio minus one) — so at 10:1, clearance is swept volume divided by 9.
Standards and references behind these figures
The arithmetic on this page is fixed, but the boundaries and conventions around it come from published standards and manufacturer guidance. These are the documents they come from, so you can check them rather than take them on trust.
01Chevy Hardcore — compression ratio and pump gas compatibilityPiston-manufacturer guidance on the practical compression limits for iron and aluminium heads on pump fuel.↗02Ford Performance — dynamometer testing and engine performance tech tipsManufacturer guidance on dyno correction and how quoted power figures are arrived at.↗Nominal dimensions, not checked ones. These results are only as good as the figures entered. On a rebuilt engine, bore, chamber volume and deck clearance all differ from the published specification — sometimes considerably. Where the answer matters, measure the chamber with a burette and check deck clearance rather than trusting a casting number.