Calculate static and dynamic compression ratio from bore, stroke, gasket, deck, and chamber volume. Get displacement, horsepower estimate, and octane recommendations.
Enter cylinder dimensions and volumes
Positive = dome (adds CR), Negative = dish (reduces CR)
For dynamic CR (typical 55–80°)
Displacement change across different bore sizes (same stroke)
Cylinder Diagram
Swept Volume
Vs = π/4 × B² × S
Clearance Volume
Vc = Ch + Gk + Dk − Dm
Static CR
CR = (Vs + Vc) / Vc
Dynamic CR
DCR = CR × EVC factor