What is the formula for engine displacement?

Displacement = (π/4) × bore² × stroke × number of cylinders. Bore and stroke must be in the same unit; the result is in the cubed form of that unit (e.g., mm inputs → mm³, then divided by 1,000 for cc).

What is the difference between cc and liters?

They are the same unit at a different scale. 1 liter = 1,000 cubic centimeters (cc). A 2,000 cc engine is a 2.0-liter engine.

What is a cubic inch (cu-in or CID)?

Cubic inch displacement is the traditional US measurement for engine size. 1 cubic inch = 16.387 cc. A 350 CID V8 is approximately 5.7 liters.

Does bore or stroke have more effect on displacement?

Bore has a squared effect (it appears as bore²) while stroke is linear. Doubling the bore quadruples the per-cylinder displacement; doubling the stroke only doubles it. Over-square engines (bore > stroke) rev freely; under-square engines (stroke > bore) produce more torque at lower rpm.

Can I use this for single-cylinder engines?

Yes. Enter 1 as the number of cylinders to calculate the displacement of a single cylinder, useful for motorcycle engines, small equipment, or per-cylinder analysis.

Does changing units convert existing values?

No. Switching between Metric and Imperial changes only the unit label. You must re-enter values in the new unit system — the calculator does not auto-convert previously typed numbers.

Displacement From Bore & Stroke

Enter bore, stroke, and cylinder count to calculate total engine displacement in cc, liters, and cubic inches instantly.

Cylinder Dimensions

Bore (mm)

Stroke (mm)

Number of Cylinders

Common Displacements

600 cc

Motorcycle inline-4

2.0 L

Compact car 4-cyl

5.7 L

350 CID V8

Enter bore, stroke, and cylinders on the left

Summary

This tool computes total engine displacement using the standard formula: Displacement = (π/4) × bore² × stroke × cylinders. Results are shown simultaneously in cubic centimeters (cc), liters, and cubic inches so you can compare across unit systems. Both metric (millimeters) and imperial (inches) input modes are supported, with instant recalculation on every keystroke.

How it works

Select your input unit system — Metric (mm) or Imperial (inches).
Enter the cylinder bore diameter.
Enter the piston stroke length.
Enter the number of cylinders (1–16).
Total displacement appears immediately in cc, liters, and cubic inches.
Use the Reset button to clear all fields and start a new calculation.

Use cases

Verify engine size when purchasing or rebuilding an engine.
Convert a bore/stroke combination to cc or liters for classification.
Compare displacement of different bore and stroke configurations during engine planning.
Check that a stroker or big-bore kit hits the desired displacement target.
Determine cubic inch displacement from a metric bore/stroke spec sheet.
Calculate single-cylinder displacement for engine balance analysis.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu