Compression Ratio Calculator

Use This Free Tool To Compute Your Compression

Instructions: Enter a value in the un-shaded boxes below as they pertain to your engine.

Note: For pistons BELOW the block @ TDC - value in box must be a POSITIVE number (.000)

Note: For pistons ABOVE the block @ TDC - value in box must be a NEGATIVE number (-.000)

Note: For a DISH piston - value in box must be a POSITIVE number (0.0)

Note: For a DOME piston - value in box must be a NEGATIVE number (-0.0)

Note: Manipulate the DOME/DISH & PISTON to DECK volumes to get the ratio you want.

Enter the number of cylinders of your engine			>
Bore	>	Finished bore of your engine	>
Stroke	>	Stroke of your engines crankshaft	>
Rod Length	>	Ctr. to Ctr. length of your connecting rods	>
Gasket Bore	>	Head Gasket bore diameter	>
Comp. Gasket	>	Compressed Head Gasket thickness	>
Block Deck Height	>	Center of main bearing bore to top of block	>
Top Ring Down	>	Top of 1st ring to top of pistons (FLAT)	>
Chamber Volume	>	Cylinder Head chamber volume in CC's	>
Dome/Dish Volume	>	DOME (-) or DISH (+) vol. (theoretical) in CC's	>
Piston to Deck	>	Top of BLOCK to top of piston (FLAT) @ TDC	>
Click "Calculate" for dimension results.
Total Volume	>		>
Cylinder Volume	>	Total cylinder volume in CC's =	>
Clearance Volume	>	All effective vol. above block deck @ TDC in CC's =	>
Gasket Volume	>	Volume of your head gasket in CC's =	>
Top Ring Volume	>	Total volume above the top ring @ TDC in CC's =	>
Deck Volume	>	Volume of area above the pistons @ TDC in CC's =	>
Piston Top Land	>	Piston top land diameter for volume calculations =	>
1/2 Stroke	>	1/2 stroke of your engine's crankshaft in inches =	>
Compression Ht.	>	Ctr. of piston pin to top of piston (FLAT) in inches =	>
Cubic Inches	>	Cubic inch displacement of your engine =	>
For the given dimensions, your compression ratio =			>

If you are having problems computing your compression ratio, please refer to the "notes" on top and re-check your numbers or please call tech assistance.