Engine Displacement Calculator
Calculate engine displacement from bore and stroke. Works in inches or millimeters — converts between CID, cc, and liters.
Cylinder bore diameter
Piston stroke length
Number of cylinders
Famous Engine Reference
Click any engine to load its specs into the calculator
About Engine Displacement
Engine displacement is the total volume swept by all pistons in one complete stroke cycle. A larger bore increases displacement faster than a longer stroke — a "overbored" engine (wider bore, same stroke) will be more rev-happy and free-breathing, while a "stroked" engine (same bore, longer stroke) produces more torque at lower RPM. Most classic American V8s use a bore-to-stroke ratio near 1:1, while high-revving motors tend to be oversquare (bore > stroke).
Oversquare
Bore > Stroke
High-revving
Square
Bore = Stroke
Balanced
Undersquare
Stroke > Bore
Torquey