Find an engine’s total displacement — the combined swept volume of all its cylinders — from bore, stroke, and cylinder count.
How it works
Each cylinder’s volume is modeled as a simple cylinder: displacement = (π ÷ 4) × bore² × stroke × cylinders. A 4-cylinder engine with an 8.6 cm bore and 8.6 cm stroke displaces about 1,998 cm³ — close to a real 2.0-liter engine.
What this does not include
This models each cylinder as a perfect geometric cylinder. It doesn’t account for combustion chamber shape, valve pockets, or other real engine geometry that causes a manufacturer’s stated displacement to differ very slightly from this pure geometric calculation.
How to use this calculator
- Enter the cylinder bore diameter.
- Enter the piston stroke length.
- Enter the number of cylinders.
A worked example
A 4-cylinder engine with 8.6 cm bore and stroke: displacement = 1998.2289 cc (≈2.0 liters).
An 8-cylinder engine with 10.2 cm bore, 8.85 cm stroke: displacement = 5785.268 cc (≈5.8 liters).
What the variables mean
| Variable | Meaning |
|---|---|
| Bore | Cylinder diameter |
| Stroke | Distance the piston travels inside the cylinder |
| Cylinders | Number of cylinders in the engine |
Edge cases worth knowing
Total displacement scales directly with cylinder count — doubling the number of identical cylinders exactly doubles total displacement, which is why V8 engines typically displace far more than 4-cylinder engines even with similar bore and stroke.
A bore of zero collapses the cylinder to nothing, so the calculator declines to show a result for that input.
What’s the difference between bore and stroke?
Bore is the cylinder’s diameter; stroke is the distance the piston travels up and down inside it — together they define how much volume each cylinder sweeps per cycle.
Why is displacement usually expressed in liters or cc?
A liter (1,000 cm³) gives a convenient, easy-to-compare figure for total engine size — a “2.0-liter engine” is immediately more meaningful than its displacement in cubic inches or cubic centimeters alone.
Does a bigger displacement always mean more power?
Generally larger displacement allows for more power, but actual output also depends heavily on other factors like turbocharging, compression ratio, and engine tuning.
