Engine Displacement Calculator

Start by selecting a common engine preset from the dropdown menu, or enter your measurements manually. If you choose a preset, the bore, stroke, and cylinder count will fill in automatically using standard factory specifications in inches.

For manual entry, type the bore (cylinder diameter) and stroke (piston travel distance) into their respective fields. Use the unit toggle next to each input to switch between inches and millimeters. Then select the number of cylinders from the dropdown.

Results update instantly and show total displacement in cubic inches, cubic centimeters, and liters. You will also see the single cylinder volume, bore to stroke ratio with its classification (oversquare, square, or undersquare), and, when applicable, the common marketing name for that displacement size.

Engine displacement is the total volume swept by all pistons inside the cylinders during one complete engine cycle. It is one of the most fundamental specifications for any internal combustion engine and serves as a rough indicator of the engine's power potential, fuel consumption, and physical size.

The formula uses the cylinder bore (diameter), the piston stroke (travel distance from top dead center to bottom dead center), and the number of cylinders. Mathematically, each cylinder's volume is the area of the bore circle multiplied by the stroke length. Multiply that by the number of cylinders and you get total displacement.

Displacement does not tell you everything about an engine's output. Factors like compression ratio, valve timing, forced induction, and fuel delivery all play major roles in determining actual horsepower and torque. However, displacement sets the baseline. All else being equal, a larger displacement engine can move more air and fuel per revolution and produce more power.

The relationship between bore and stroke determines much of an engine's personality. An oversquare engine, where the bore is larger than the stroke, can accommodate larger intake and exhaust valves. Bigger valves mean better airflow, especially at high RPM, which is why performance engines like the Chevy LS3 and many racing motors use oversquare designs. The shorter stroke also reduces piston speed at any given RPM, which lowers mechanical stress and allows higher redlines.

An undersquare engine, with a longer stroke than bore, generates more leverage on the crankshaft. This produces higher torque at lower RPM, making undersquare designs ideal for trucks, diesel engines, and applications where pulling power matters more than peak horsepower. The tradeoff is that longer strokes create higher piston speeds, which limits how high the engine can safely rev.

A square engine, where bore and stroke are nearly identical, offers a compromise. The Toyota 2JZ is a well known example with an 86mm bore and 86mm stroke. Square engines tend to produce a flat, usable power band across a wide RPM range, making them versatile for both street and performance use.

The Chevrolet small block is one of the most widely produced engine families in history. The classic 350 (5.7L) uses a 4.000 inch bore and 3.480 inch stroke in a V8 configuration. The modern LS3 displaces 376 cubic inches (6.2L) with a slightly larger bore and longer stroke while maintaining the same basic V8 layout.

Ford's small block family includes the legendary 302 (5.0L) and the modern Coyote 5.0, which achieves similar displacement with different bore and stroke dimensions. The Coyote uses a smaller bore and longer stroke compared to the original 302, combined with dual overhead cams and four valves per cylinder for dramatically different performance characteristics.

Japanese engines like the Honda B18 and Toyota 2JZ achieve their displacement with fewer, larger cylinders relative to their displacement class. The 2JZ's inline six layout with equal bore and stroke is legendary for its smooth power delivery and exceptional strength, which is why it remains a popular choice for high horsepower builds decades after production ended.

Chrysler's Hemi engines, including the 5.7L and 6.2L Hellcat, use hemispherical combustion chambers and relatively large bores to maximize valve area and airflow. The Hellcat's supercharged 6.2L produces over 700 horsepower from the factory, demonstrating how forced induction can extract massive power from a given displacement.