Engine Displacement Calculator
Calculate engine displacement from bore, stroke, and number of cylinders. Results in cc, cubic inches, and liters.
What is Engine Displacement?
Displacement is the total volume swept by all pistons in one complete engine cycle. It's the most basic measure of engine size and a primary factor in power output potential.
The Formula
Displacement = (π/4) × Bore² × Stroke × Number of Cylinders
This gives you the swept volume — the space the pistons travel through. It does not include the combustion chamber volume (that's what compression ratio accounts for).
Bore/Stroke Ratio
- Oversquare (ratio > 1.0) — bore is larger than stroke. Allows bigger valves, breathes better at high RPM. Common in performance engines.
- Undersquare (ratio < 1.0) — stroke is longer than bore. Better leverage on the crankshaft, stronger low-end torque. Common in truck and diesel engines.
- Square (ratio ≈ 1.0) — balanced design. Good all-around power band.
Common Conversions
- 1 Liter = 61.024 cubic inches
- 1 cubic inch = 16.387 cc
- Example: 350 ci = 5.735L, 5.7L ≈ 346 ci
Frequently Asked Questions
How is engine displacement calculated?
Displacement = (π/4) × bore² × stroke × number of cylinders. For example, a V8 with a 4.000" bore and 3.480" stroke: (3.14159/4) × 4.000² × 3.480 × 8 = 349.8 cubic inches (5.7 liters). The bore and stroke must be in the same unit.
What is the difference between bore and stroke?
Bore is the diameter of the cylinder. Stroke is the distance the piston travels from top dead center (TDC) to bottom dead center (BDC). An engine with a larger bore than stroke is called oversquare (revs freely, good for high RPM). An engine with a longer stroke than bore is undersquare (more torque at lower RPM).
How do I convert between cubic inches, cc, and liters?
1 cubic inch = 16.387 cc. 1 liter = 1000 cc = 61.024 cubic inches. So a 350 cubic inch engine is 5735 cc or 5.7 liters. A 2.0L engine is 2000 cc or 122 cubic inches.
Related Articles
How engine displacement is calculated from bore and stroke, the difference between oversquare and undersquare designs, and how displacement affects power and torque character.
Engine BuildingChoosing the Right Carburetor: CFM Sizing, Types, and Common MistakesHow to pick the right carburetor for your engine — CFM calculation, vacuum vs mechanical secondaries, and the mistakes that kill performance.
Engine BuildingVolumetric Efficiency Explained: What VE Means and Why It MattersWhat volumetric efficiency is, how it's measured, what affects it, and why VE is the single best indicator of how well your engine breathes.
Engine BuildingCompression Ratio Explained: How to Calculate, Measure, and OptimizeEverything you need to know about compression ratio — how to calculate it, how to measure it, and how to choose the right CR for your fuel, cam, and boost level.
Engine BuildingPiston Speed and Rod Ratio: What They Mean for Your EngineHow mean piston speed limits RPM, what rod ratio affects, and how to use these numbers when planning a stroker build or choosing an RPM range.
Engine BuildingExhaust Sizing Guide: How to Pick the Right Pipe and Header SizeHow to size exhaust pipes and header primaries based on horsepower, why bigger isn't always better, and how exhaust flow affects torque and power curves.
Related Calculators
Calculate static compression ratio from bore, stroke, chamber volume, head gasket, deck clearance, and piston dome or dish volume.
Piston SpeedCalculate mean piston speed from engine stroke and RPM. Results in ft/min, m/s, mph, and km/h with safety benchmarks for street, race, and extreme applications.
Rod RatioCalculate connecting rod ratio from rod length and stroke. Shows rod angle, piston dwell, acceleration characteristics, and comparisons to common engines.
Carburetor CFMCalculate the ideal carburetor size in CFM from engine displacement, RPM, and volumetric efficiency. Recommends the nearest common carburetor size.