Engine Displacement Calculator

The Engine Displacement Calculator works out the total displacement of an engine from its bore, stroke, and number of cylinders. It gives you the result in cubic centimetres (cc), liters (L), and cubic inches (CID) at once, shows the displacement of a single cylinder, and — uniquely — analyses your bore/stroke ratio to tell you whether the engine is oversquare, square, or undersquare, alongside an animated, to-scale piston diagram.

What is Engine Displacement?

Engine displacement is the total volume swept by all of the pistons as they travel through their stroke. It represents the amount of air-fuel mixture an engine can draw in during one full cycle, which is why it is one of the most important indicators of an engine's size and power potential. A 2.0-liter engine, for example, displaces 2000 cubic centimetres across all of its cylinders combined.

Engine Displacement Formula

The displacement of a single cylinder is the volume of a cylinder (a circle swept along the stroke length). Multiply by the number of cylinders for the total.

When bore and stroke are entered in millimetres, the result is in cubic millimetres. Dividing by 1000 converts to cubic centimetres (cc); dividing cc by 1000 gives liters, and dividing cc by 16.387 gives cubic inches.

Bore vs Stroke: Why the Ratio Matters

The relationship between bore and stroke shapes an engine's whole character, even at the same displacement:

Common Unit Conversions

What Affects Displacement and Power?

How to Use This Calculator

1. Choose your units: Select Metric (mm) or Imperial (inch) to match how your bore and stroke are measured.
2. Enter bore and stroke: Bore is the cylinder diameter; stroke is the distance the piston travels.
3. Select the number of cylinders: Pick anything from a single-cylinder up to a V16.
4. Click Calculate: See the total displacement in cc, liters, and cubic inches, the per-cylinder volume, the bore/stroke character analysis, and a full step-by-step breakdown.

Frequently Asked Questions

What is engine displacement?

Engine displacement is the total volume swept by all the pistons inside the cylinders as they move from the bottom of their stroke to the top. It is a key measure of an engine's size and a strong indicator of its potential power and torque. Displacement is usually expressed in cubic centimetres (cc), liters (L), or cubic inches (CID).

How do you calculate engine displacement?

Displacement is calculated with the formula (π / 4) × bore² × stroke × number of cylinders. Bore is the cylinder diameter and stroke is the distance the piston travels. Using bore and stroke in millimetres gives cubic millimetres, which are divided by 1000 to convert to cubic centimetres (cc).

What is the difference between bore and stroke?

Bore is the diameter of each cylinder, while stroke is the distance the piston travels from bottom dead centre to top dead centre. A larger bore lets the engine breathe better at high RPM, while a longer stroke tends to produce more low-end torque.

What is an oversquare or undersquare engine?

An oversquare engine has a bore larger than its stroke (bore/stroke ratio greater than 1), which favours high revs and peak power. An undersquare or long-stroke engine has a stroke longer than its bore (ratio less than 1), favouring low-end torque. A square engine has a bore roughly equal to its stroke and balances the two.

How do I convert cc to liters and cubic inches?

To convert cc to liters, divide by 1000 (for example 1998 cc = 2.0 L). To convert cc to cubic inches (CID), divide by 16.387 (for example 5735 cc is about 350 CID). This calculator shows all three units at once.

Does displacement equal horsepower?

Not directly. Displacement measures engine size, not power. A larger engine has more potential to make power and torque, but the actual output also depends on the compression ratio, forced induction (turbo or supercharger), fuel, RPM, and tuning. Two engines of the same displacement can make very different horsepower.

Additional Resources

• Engine Displacement - Wikipedia
• Bore (Engine) - Wikipedia
• Stroke Ratio - Wikipedia