Engine Displacement Calculator
Enter bore, stroke, and cylinder count to find displacement in CI, CC, and liters.
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How to Calculate Engine Displacement
Engine displacement is the total volume swept by all pistons in one complete cycle. It is calculated from bore (cylinder diameter), stroke (piston travel distance), and number of cylinders.
Displacement = π/4 × bore² × stroke × cylinders. To convert cubic inches to liters, divide by 61.024. To convert to CC, multiply by 16.387.
Engine displacement = bore² × π/4 × stroke × number of cylinders. Bore and stroke must be in the same units (cm, mm, or inches). For a 4-cylinder engine with 86mm bore and 86mm stroke: (86² × π/4 × 86 × 4) / 1,000,000 = (7396 × 0.7854 × 86 × 4) / 1,000,000 ≈ 2,000cc = 2.0L.
"Square" engines have bore = stroke (like the example above). Under-square (long-stroke) engines have stroke > bore — they make more torque at lower RPM and are efficient for low-speed applications. Over-square (short-stroke) engines have bore > stroke — they rev higher and make peak power at higher RPM.
The 1,000,000 divisor converts cubic millimeters to cubic centimeters (1 cc = 1,000 mm³). To convert cc to cubic inches: divide by 16.387. The American muscle-car era 350 V8 = 350 cubic inches = 5,736cc ≈ 5.7L.
Specific output (HP per liter) measures engine efficiency. Naturally aspirated engines typically produce 50–100 HP/L; forced-induction engines can reach 150–250 HP/L. Modern high-revving naturally aspirated sports car engines (Ferrari, Honda S2000) achieve 100+ HP/L without forced induction.
See also: HP & Torque Calculator · Compression Ratio Calculator