Engine Displacement Calculator

Use the free Ken O’Connor Racing Engine Displacement Calculator to calculate total engine size in cubic centimeters (cc) and cubic inches. Enter the cylinder bore, crankshaft stroke and number of cylinders to determine the swept displacement of a two-stroke or four-stroke motorcycle, ATV or powersports engine.

KEN O’CONNOR RACING

Engine Displacement Calculator

Enter the bore, stroke and number of cylinders.

Engine Measurements
Calculated Displacement
Total Engine Displacement 195.0 cc
Cubic Inches 11.90 cu in
195.0 cc per cylinder
Formula:
π ÷ 4 × bore² × stroke × cylinders
Measurement Note Measure the actual cylinder bore and crankshaft stroke. Do not use piston size or connecting-rod length. The result is swept displacement and does not include combustion-chamber volume.
Calculator provided by Ken O’Connor Racing

How to Calculate Engine Displacement

Engine displacement is determined by the cylinder bore, crankshaft stroke and number of cylinders. The calculator uses the following formula:

π ÷ 4 × bore² × stroke × number of cylinders

Enter the actual finished cylinder bore rather than the nominal piston size. Stroke is the total distance the piston travels from top dead center to bottom dead center. Connecting-rod length does not affect engine displacement.

The result represents swept displacement. It does not include the combustion-chamber volume, head-gasket volume, piston-dome volume or piston deck clearance.

Motorcycle and ATV Engine CC Calculator

This bore and stroke calculator can be used for single-cylinder and multi-cylinder engines, including:

  • Two-stroke motorcycle engines
  • Four-stroke motorcycle engines
  • ATV and UTV engines
  • Yamaha Blaster engines
  • Big-bore engine combinations
  • Custom-stroke and stroker engines
  • Vintage powersports engines
  • Racing engine builds

Select millimeters or inches, enter the required measurements and choose the number of cylinders. The calculator will display total engine displacement, displacement per cylinder and cubic-inch displacement.

Why Accurate Bore and Stroke Measurements Matter

Even a small change in cylinder bore or crankshaft stroke can affect total engine displacement. This becomes particularly important when calculating big-bore engines, stroker combinations or engines that have been bored beyond their original factory size.

Always use the actual finished bore measurement and the crankshaft’s true stroke when making performance, compression or racing-class calculations.

Engine Machining from Ken O’Connor Racing

Ken O’Connor Racing provides professional motorcycle and ATV engine machining, including cylinder boring, power honing, crankshaft rebuilding, cylinder sleeving, cylinder-head machining and two-stroke porting. Contact us if you need help measuring or machining an engine for your next build.