Engine Displacement Calculator
This engine displacement calculator finds the total swept volume of an engine from the bore, stroke, and number of cylinders. Enter the sizes in inches or millimeters and the engine displacement calculator returns the displacement in cc, liters, and cubic inches, the volume of each cylinder, and the bore to stroke ratio.
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What the engine displacement calculator shows
Engine displacement is the volume all the pistons sweep in one stroke from bottom to top. Each cylinder is a short tube as wide as the bore and as long as the stroke, so its volume is the circle area times the stroke. The engine displacement calculator multiplies that by the number of cylinders and converts the result into the three units you see on spec sheets: cubic centimeters, liters, and cubic inches.
Engine displacement formula
Volume of one cylinder times the cylinder count:
With millimeters, divide the cubic millimeters by 1,000 for cc. With inches, the result is in cubic inches, and multiplying by 16.387 gives cc.
Engine displacement calculator example
A V8 with a 4.00 in bore and a 3.48 in stroke:
That is the classic small block 350. A four cylinder with an 86 mm bore and an 86 mm stroke gives 1,998.2 cc, sold as a 2.0 liter, with a square bore to stroke ratio of 1.
How to use the engine displacement calculator
Choose inches or millimeters, enter the bore (cylinder diameter) and the stroke (piston travel), and enter the number of cylinders. Press Calculate to read the displacement. For a rebuild, enter the overbore size, such as 4.030 in for a 350 bored 0.030 over, and the stroke of the crank you are using. A stroker crank simply changes the stroke.
Reading the engine displacement
Displacement is the size of the engine, not its power, but larger engines can move more air per revolution and usually make more torque. Makers round it for marketing, so 5.73 L becomes 5.7 L and 1,998 cc becomes 2.0 L. The bore to stroke ratio describes the character: above 1 is oversquare, which favors high RPM; below 1 is undersquare, which favors low speed torque; 1 is square.
When to use a cubic inch calculator
- Working out the size after an overbore
- Planning a stroker build
- Converting cc to cubic inches and liters
- Checking racing class limits by displacement
- Comparing engines on a spec sheet
Common engine displacement calculator mistakes
- Mixing units. Enter bore and stroke in the same unit you selected.
- Using the radius. The bore is the full cylinder diameter.
- Using connecting rod length. Stroke is the crank throw times two.
- Counting rotary engines like pistons. Wankel engines use a different method.
Tips for an accurate engine displacement figure
- Measure the bore with a dial bore gauge below the ring ridge.
- Read the stroke from the crank spec, not the piston travel by hand.
- Use the finished bore size after machining for the final figure.
Stroker displacement calculator: changing bore and stroke
There are two ways to add displacement: bore the cylinders bigger or lengthen the stroke with a different crankshaft. Because the bore is squared, a small overbore adds a modest amount, while a longer stroke adds volume in direct proportion. Taking the 350 to a 3.75 in stroker crank with a 4.030 in bore gives about 383 cu in, the well known 383 stroker, which is why stroker kits are the favorite way to make a small block bigger. Longer strokes raise piston speed at a given RPM and can need different rods or pistons, clearancing of the block, and a balanced rotating assembly. Run the new size through the compression ratio calculator too, since the larger swept volume raises compression with the same heads.
Cubic inches to liters and cc to cubic inches
American engines were sold by cubic inches for decades and are still known that way, while most other markets use liters or cc. The conversions are fixed: 1 cubic inch is 16.387 cc, 1 liter is 1,000 cc, and so 1 liter is 61.02 cubic inches. A 5.0 liter Ford is 302 cu in, a 5.7 liter is 350, and a 6.2 liter is about 376. Motorcycles and small engines are almost always quoted in cc, so a 1,200 cc twin is 73.2 cu in. Once you have the size, the horsepower calculator relates the torque the engine makes to its power at a given RPM.
Engine displacement chart
Displacement from bore and stroke for well known engines:
| Engine | Bore × stroke | Cylinders | Displacement |
|---|---|---|---|
| Small block 350 | 4.00 × 3.48 in | 8 | 349.8 cu in / 5,733 cc |
| Small block 302 | 4.00 × 3.00 in | 8 | 301.6 cu in / 4,942 cc |
| 426 Hemi | 4.25 × 3.75 in | 8 | 425.6 cu in / 6,974 cc |
| Big block 454 | 4.25 × 4.00 in | 8 | 454.0 cu in / 7,439 cc |
| 2.0 L square four | 86 × 86 mm | 4 | 121.9 cu in / 1,998 cc |
| 1.6 L four | 81 × 77.4 mm | 4 | 97.4 cu in / 1,595 cc |
Engine Displacement Calculator FAQ
How do you calculate engine displacement?
Multiply π ÷ 4 by the bore squared, by the stroke, and by the number of cylinders. With inches you get cubic inches; with millimeters divide by 1,000 for cc.
How many cc is 350 cubic inches?
About 5,735 cc, since one cubic inch is 16.387 cc. The 350 small block computes to 349.8 cu in, or 5,733 cc.
How much does a 0.030 overbore add?
On a 350 small block, boring from 4.000 to 4.030 in raises the displacement to about 355 cu in.
Does displacement include the combustion chamber?
No. Displacement is only the swept volume. The chamber and other clearance volumes go into the compression ratio.