Engine Displacement Calculator

Both measure the same thing (total swept volume of every cylinder combined), just in different units. 1 cubic inch equals exactly 16.387064 cubic centimeters, fixed by the 1959 International Yard and Pound Agreement (1 inch is defined as 25.4 mm exactly, so 1 in^3 = 25.4^3 mm^3 = 16,387.064 mm^3 = 16.387064 cc). A 350 ci small-block Chevy is 5,735 cc, or 5.7 liters. Cubic centimeters and milliliters are the same unit, which is why motorcycle people say "600 cc" and chemists say "600 mL" for the same volume.

Stroke divided by bore tells you the engine's geometry, and engineers reach for one of three labels based on the result. Below 1.0 is oversquare (a short-stroke, big-bore engine that loves to rev, like a Honda S2000 with an 87 mm bore and 84 mm stroke giving 0.97). Above 1.0 is undersquare (a long-stroke, narrow-bore engine that makes torque low and burns less fuel cruising, like a diesel truck engine at 1.20 or higher). Exactly 1.0 is square (the Honda K20 at 86 x 86 mm and the original 350 small-block Chevy both sit here). Oversquare engines breathe better at high RPM because larger valves fit in a bigger bore; undersquare engines extract more force on each power stroke because the longer crankshaft throw gives the connecting rod more leverage.

Look for a line that reads something like "Bore x Stroke: 86 x 86 mm" in the technical specifications section of the manual, the manufacturer's press release, or a sales brochure. American V8 specs often list inches: "4.00 x 3.48 in" is a 5.7 L LS1. Both numbers are physical dimensions of one cylinder: bore is the inside diameter of the cylinder wall, stroke is the distance the piston travels from top dead center to bottom dead center. Engine wear can change bore (an over-bored rebuild adds 0.020 inch or so to the original spec); stroke is set by the crankshaft and only changes if you swap to a stroker crank.

Displacement scales linearly with cylinder count, so swapping a 4-cylinder for a 6-cylinder at the same bore and stroke adds 50% more cubic centimeters. A 500 cc single-cylinder bike and a 4-cylinder 2,000 cc car both run on per-cylinder volumes of 500 cc, but the car makes more total power, smoother torque, and runs at higher RPM with the same piston speed. More cylinders also let an engine make the same total displacement with smaller, lighter pistons that survive higher RPM (the F1 V12s of the early 1990s held 3.5 L across 12 cylinders for 290 cc each, which is why they redlined at 15,000 RPM).

Divide by 1000. A 2,000 cc engine is 2.0 liters. A 5,735 cc small-block Chevy is 5.7 liters, which is why it's marketed as a "5.7 L V8". 1 cubic centimeter and 1 milliliter are the same volume, and 1 liter is 1000 mL, so the cc-to-liter step is just a decimal shift. Manufacturers round to one decimal place for marketing ("3.5 L V6") even when the actual displacement is 3,471 cc; the calculator shows two decimal places so you can spot the difference between a 1.99 L and a 2.01 L engine that both get badged as "2.0".