I'll try to make this as simple as possible...But this is for Static Compression, not Dynamic Compression.
Comp Ratio = (Total Chamber Volume + Swept Volume)/Total Chamber Volume
Swept Volume = 'pi' x (Bore/2) x (Bore/2) x Stroke
Total Chamber Volume = Combustion Chamber Volume + Head Gasket Volume + Deck Clearance Volume + Valve Relief Pocket Volume + Crevice Volume
