Engine Displacement Calculator
Calculate engine displacement from bore, stroke and cylinder count — instantly, in cubic inches, cc and liters. Includes a reverse solver (find bore, stroke or cylinders from a known displacement), bore/stroke ratio classification, a CFM airflow estimate, and one-click presets for famous engines like the Chevy 350. Everything runs in your browser — no sign-up, no data leaves your device.
100% client-sideinch ⇄ mmci ⇄ cc ⇄ LReverse solverCalculator
Results
Famous engine presets
Tap any engine to load its bore, stroke and cylinder count into the calculator.
| Engine | Bore | Stroke | Cyl | Displacement |
|---|
How to calculate engine displacement
Engine displacement — also called swept volume — is the volume all pistons sweep as they travel from bottom dead center (BDC) to top dead center (TDC). The engine displacement formula is:
Keep bore and stroke in the same unit: inches in → cubic inches out; centimeters in → cubic centimeters (cc) out. For liters, convert: 1 in³ = 16.3871 cc and 1000 cc = 1 L (so divide cubic inches by 61.0237).
Worked example: the Chevy 350
- Bore = 4.00 in, stroke = 3.48 in, 8 cylinders. Square the bore: 4.00² = 16.
- Multiply by π/4: 16 × 0.785398 = 12.5664 (this is the piston's cross-sectional area in in²).
- Multiply by stroke: 12.5664 × 3.48 = 43.731 (swept volume of one cylinder, in³).
- Multiply by cylinders: 43.731 × 8 = 349.85 cubic inches ≈ 5.73 liters.
Bore/stroke ratio: oversquare, square, undersquare
The ratio bore ÷ stroke shapes an engine's character. This calculator reports it automatically:
| Type | Ratio | Typical character |
|---|---|---|
| Oversquare (short-stroke) | > 1.02 | Revs higher, more top-end horsepower — typical of performance and motorcycle engines (e.g. Honda B18: 81/87.2 ≈ 0.93 is actually undersquare; a Chevy 350 at 4.00/3.48 = 1.15 is oversquare). |
| Square | ≈ 1.00 | Balanced power and efficiency — e.g. Toyota 2JZ: 86/86 = 1.00. |
| Undersquare (long-stroke) | < 0.98 | More low-RPM torque, better for towing and economy — e.g. Harley 1200: 3.497/3.81 = 0.92. |
Engine size classes
Displacement in liters doubles as a rough size class. "Small block" vs "big block" is a Chevrolet V8 family distinction, but displacement is the number people quote:
| Displacement | Class / context | Example |
|---|---|---|
| Under 1.0 L | Scooter / kei-car class | Honda CB750: 0.89 L |
| 1.0 – 2.0 L | Compact / sport-compact | Honda B18: 1.8 L |
| 2.0 – 3.5 L | Midsize / performance six | Toyota 2JZ: 3.0 L · BMW S54: 3.2 L |
| 3.5 – 5.7 L | Full-size / small-block V8 | Ford 302: 4.9 L · Chevy 350: 5.7 L |
| 5.7 – 7.5 L | Big-block / large V8 | Chevy 454: 7.4 L |
| Over 7.5 L | Heavy-duty / industrial | Truck & marine diesels |
Cubic inches to liters & cc — quick reference
| Cubic inches (ci) | cc | Liters | Known as |
|---|---|---|---|
| 73.2 | 1,199 | 1.20 | Harley Sportster 1200 |
| 109.7 | 1,797 | 1.80 | Honda B18 |
| 182.9 | 2,997 | 3.00 | Toyota 2JZ |
| 301.6 | 4,942 | 4.94 | Ford 302 "5.0" |
| 349.8 | 5,733 | 5.73 | Chevy 350 "5.7" |
| 454.0 | 7,439 | 7.44 | Chevy 454 big block |
Conversions: ci × 16.3871 = cc · cc ÷ 1000 = liters · ci ÷ 61.0237 = liters.
Scope boundary
This tool computes swept volume only — the geometry of bore, stroke and cylinder count. It does not compute compression ratio (which needs clearance/chamber volume), mean piston speed, horsepower/torque, fuel requirements, or carburetor sizing. The CFM figure is a 4-stroke intake-airflow estimate for context, not a carburetor recommendation.
Frequently asked questions
What is engine displacement?
Engine displacement is the total swept volume of all pistons in an engine — the volume each piston displaces as it travels from bottom dead center (BDC) to top dead center (TDC), multiplied by the number of cylinders. It is the standard measure of engine size, expressed in cubic inches (ci/cid), cubic centimeters (cc) or liters (L).
What is the engine displacement formula?
Displacement = (π/4) × bore² × stroke × number of cylinders. Bore and stroke must be in the same unit: if both are in inches the answer is in cubic inches; if both are in centimeters the answer is in cubic centimeters (cc).
How do I calculate engine displacement with bore and stroke?
Square the bore, multiply by the stroke, multiply by π/4 (0.7854), then multiply by the number of cylinders. Example: a 4.00-inch bore, 3.48-inch stroke, 8-cylinder engine gives 0.7854 × 16 × 3.48 × 8 = 349.85 cubic inches (the classic Chevy 350).
How do I convert cubic inches to liters?
Multiply cubic inches by 0.0163871 to get liters (1 cubic inch = 16.3871 cc, and 1000 cc = 1 liter). Equivalently, divide cubic inches by 61.0237. Example: 349.85 ci × 0.0163871 = 5.73 liters.
How many cc are in a cubic inch?
One cubic inch equals 16.3871 cubic centimeters (cc). To convert engine displacement from cubic inches to cc, multiply by 16.3871; to go from cc to cubic inches, divide by 16.3871.
How do I convert engine cc to liters?
Divide cc by 1000 to get liters: 1 liter = 1000 cubic centimeters. For example, a 1797 cc Honda B18 engine is a 1.8-liter engine, and a 2997 cc Toyota 2JZ is a 3.0-liter engine.
What does a 350 engine mean in liters?
A "350" is 350 cubic inches of displacement, which converts to about 5.73 liters (350 ÷ 61.0237). The Chevrolet 350 small block — 4.00-inch bore, 3.48-inch stroke, 8 cylinders — is the textbook example at 349.85 ci.
What is bore vs stroke in an engine?
Bore is the diameter of the cylinder (the width the piston moves in); stroke is the distance the piston travels up and down inside the cylinder, set by the crankshaft. Together with cylinder count they fully determine displacement.
What is an oversquare vs undersquare engine?
An oversquare engine has a bore larger than its stroke (ratio above 1) and typically revs higher with more top-end power; an undersquare (long-stroke) engine has a stroke longer than its bore and typically makes more low-RPM torque. A square engine has bore equal to stroke.
Can I find the bore if I know the engine displacement?
Yes — invert the formula: bore = √((4 × displacement) ÷ (π × stroke × cylinders)). The reverse solver on this page does that for you, and can also solve for stroke or cylinder count from a known displacement.
Does bigger engine displacement mean more power?
Generally yes — a larger displacement can burn more air and fuel per cycle, which usually means more torque and power potential. But forced induction, compression ratio, valve timing, RPM range and tuning matter enormously: a turbocharged 2.0-liter can outrun a lazy 5.0-liter V8.
What is the difference between engine displacement and compression ratio?
Displacement (swept volume) is the volume the pistons sweep through; compression ratio is the ratio of the cylinder's maximum volume (swept volume plus clearance volume) to its minimum clearance volume at TDC. Displacement measures size, compression ratio measures how tightly the mixture is squeezed.
How do I calculate motorcycle engine displacement in cc?
Use bore and stroke in millimeters: displacement (cc) = (π/4) × bore_mm² × stroke_mm × cylinders ÷ 1000. Example: 67 mm bore × 63 mm stroke × 4 cylinders = 888.5 cc (Honda CB750).
Is the displacement formula the same for 2-stroke and 4-stroke engines?
Yes — swept volume is pure geometry and identical for both. The difference is airflow: a 2-stroke fires every revolution while a 4-stroke fires every other revolution, so at the same displacement and RPM a 2-stroke moves roughly twice the air-fuel mixture.