Engine Displacement Calculator

Enter the bore, stroke and number of cylinders and get the displacement in cubic inches, cc and litres, the bore-to-stroke ratio, or the bore needed for a target size.

Auto & MechanicalWorldwideSource: Swept-volume formula (stroke × π × (bore ÷ 2)² × cylinders)Free, no sign-up

Units

Bore (in)

Stroke (in)

Cylinders

The result updates as you type.

Engine displacement

349.8 cubic inches · 5.73 L

5,733 cc · 717 cc per cylinder · bore/stroke 1.149

Per cylinder	716.6 cc (43.73 ci)
Total	5,733 cc = 349.85 ci = 5.733 L
Bore-to-stroke ratio	1.149 (oversquare)

What this page cannot tell you

Whether an overbore is safe for your block, or what a build will make in power. Marketing displacement figures are often rounded, so a '5.7 L' engine computes to 5.73. Measure the actual bore after machining for a rebuilt engine.

Bore needed for a target displacement

Target displacement (cc)

Uses the stroke and cylinders above.

How to calculate engine displacement

Choose units. Inches or millimetres.
Enter bore and stroke. Cylinder diameter and piston travel, from a spec sheet or measurement.
Enter the cylinders. 4, 6, 8 — any whole number.
Read the displacement. Cubic inches, cc and litres; optionally find the bore for a target size.

10 situations where an engine displacement calculator helps

Planning an overbore

See what a .030 or .060 overbore does to cubic inches.

Stroker builds

Change the stroke to see the displacement of a stroker crank.

Checking a spec sheet

Confirm a quoted displacement from bore and stroke.

Converting cc to cubic inches

Compare a metric engine with an American one.

Motorcycle and small engines

Single and twin cylinders in millimetres.

Racing class limits

Check a build stays under a class's displacement cap.

Registration or insurance forms

Some ask for cc; get it from bore and stroke.

Bore-to-stroke ratio

See whether an engine is oversquare or undersquare.

Choosing pistons

Find the bore needed for a target displacement.

Learning engine basics

A worked example of swept volume.

The formula

Engine displacement is the volume swept by all the pistons: stroke × π × (bore ÷ 2)² × number of cylinders, as given in the Wikipedia article 'Engine displacement'. A cubic inch is exactly 16.387064 cubic centimetres (1 in = 2.54 cm), and a litre is 1,000 cc.

Example: a 4.00 in bore and 3.48 in stroke V8 is 3.48 × π × 2² × 8 = 349.9 cubic inches — the familiar '350' — or 5.73 litres. An 86 × 86 mm four-cylinder is 1,998 cc.

Limits: displacement says nothing about whether a block can safely be overbored, or what power a build makes. Advertised displacements are often rounded, so computed figures differ slightly. Combustion chamber volume, needed for compression ratio, isn't part of displacement. Everything runs in your browser.

Sources

Wikipedia — Engine displacement — Displacement = stroke × π × (bore/2)² × cylinders

Frequently asked questions

How do I calculate engine displacement?

Multiply π × (bore ÷ 2)² × stroke for one cylinder, then by the number of cylinders.

How many cubic inches is a 350?

4.00 in bore × 3.48 in stroke × 8 cylinders = 349.9 cubic inches.

How do I convert cc to cubic inches?

Divide cc by 16.387064. 5,000 cc is 305 cubic inches.

What does a .030 overbore add?

Enter the bore plus 0.030 in and compare — on a 350 it goes from 349.9 to about 355 cubic inches.

What does oversquare mean?

The bore is larger than the stroke (ratio above 1).

Does this give compression ratio?

No — that needs combustion chamber, gasket and piston volumes too.