Engine Displacement Calculator
Calculate engine size from bore, stroke, and cylinder count in either inches or millimeters. Get displacement in cubic inches (CID), liters, and cubic centimeters (cc), plus per-cylinder volume.
Engine Displacement Calculator
Cylinder diameter.
Crankshaft stroke length.
Common values: 1, 2, 3, 4, 6, 8, 10, 12.
Use with “Solve for bore” or “Solve for stroke”.
Total displacement
Cubic inches (CID)
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Liters
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Cubic centimeters (cc)
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Per-cylinder volume
CID per cylinder
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cc per cylinder
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Bore & stroke (inches)
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Bore & stroke (mm)
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Load common engine examples
How this engine displacement calculator works
Engine displacement is the total swept volume of all cylinders in an engine. It’s one of the key specs that enthusiasts use to describe engines: 350 small-block, 2.0L turbo four, 600 cc bike engine, and so on.
This calculator lets you:
- Enter bore, stroke, and number of cylinders in either inches or millimeters.
- Instantly see total displacement in cubic inches (CID), liters, and cubic centimeters (cc).
- See per-cylinder volume in CID and cc.
- Work backwards from a target displacement to solve for the required bore or stroke.
Engine displacement formula
For a single cylinder, the swept volume is the volume of a cylinder:
Single-cylinder displacement
\[ V_\text{cyl} = \pi \times \left(\frac{\text{bore}}{2}\right)^2 \times \text{stroke} \]
Total displacement for an engine with \(N\) cylinders:
\[ V_\text{total} = V_\text{cyl} \times N \]
As long as bore and stroke are in the same length unit (all inches or all millimeters), the formula works. The calculator converts everything internally and then outputs:
- Cubic inches (CID)
- Liters (L)
- Cubic centimeters (cc)
Unit conversions used
- 1 inch = 25.4 mm
- 1 cubic inch ≈ 16.387064 cc
- 1 liter = 1,000 cc
- 1 liter ≈ 61.0237441 cubic inches
Example: classic Chevy 350 small-block
A typical 350 CID Chevy small-block has:
- Bore = 4.000 in
- Stroke = 3.480 in
- Cylinders = 8
Single-cylinder volume:
\[ V_\text{cyl} = \pi \times (4.000/2)^2 \times 3.480 = \pi \times 2^2 \times 3.480 \approx 43.7 \text{ in}^3 \]
Total displacement:
\[ V_\text{total} = 43.7 \times 8 \approx 349.6 \text{ in}^3 \approx 350 \text{ CID} \]
In liters:
\[ 350 \text{ in}^3 \times 16.387 \text{ cc/in}^3 \approx 5{,}735 \text{ cc} \approx 5.7 \text{ L} \]
Reverse calculations: sizing bore or stroke for a target displacement
Sometimes you know the displacement you want (e.g., 383 CID stroker) and the number of cylinders, and you want to see what bore or stroke is required.
Solve for bore
Rearrange the formula to solve for bore, given target displacement \(V_\text{total}\), stroke, and cylinder count \(N\):
\[ V_\text{cyl} = \frac{V_\text{total}}{N} \]
\[ V_\text{cyl} = \pi \times \left(\frac{\text{bore}}{2}\right)^2 \times \text{stroke} \]
Solve for bore:
\[ \text{bore} = 2 \times \sqrt{\frac{V_\text{cyl}}{\pi \times \text{stroke}}} \]
Solve for stroke
Similarly, solving for stroke:
\[ \text{stroke} = \frac{V_\text{cyl}}{\pi \times \left(\frac{\text{bore}}{2}\right)^2} \]
The “Solve bore from target” and “Solve stroke from target” buttons apply these formulas automatically, handling all unit conversions for you.
Common questions about engine displacement
Does displacement affect power?
Displacement is one factor in potential power output: larger engines can move more air and fuel per revolution. However, actual horsepower also depends on:
- Volumetric efficiency (how well the cylinders fill with air)
- RPM range
- Compression ratio
- Fuel and ignition tuning
- Forced induction (turbo/supercharger)
Why do some engines have the same displacement but different power?
Two engines with the same displacement can have very different designs: cam profiles, valve sizes, intake and exhaust flow, boost pressure, and redline. Displacement tells you how big the engine is, not how efficiently it uses that volume.
Displacement vs. compression ratio
Displacement only includes the swept volume. Compression ratio compares the total volume at bottom dead center (swept volume + clearance volume) to the volume at top dead center (clearance volume). To compute compression ratio you also need:
- Combustion chamber volume
- Piston dish/dome volume
- Head gasket volume
- Deck clearance volume
Tips for accurate inputs
- Use precise measurements – especially when working in millimeters; small changes in bore have a big effect.
- Don’t mix units manually – let the calculator handle inch/mm conversion.
- Confirm cylinder count – V-twins, inline-3s, flat-6s, and V10/V12s are easy to miscount when working from partial specs.