If you’ve ever peeked at the specifications for a classic American car engine or a modern motorcycle, you’ve likely encountered two very different units of measurement: cubic inches and cubic centimeters. While they measure the same thing—an engine’s displacement, or total volume—they come from different measurement systems, which can be confusing. Knowing how to convert cubic inch to cc is a fundamental skill for any automotive or small engine enthusiast, allowing you to compare engines from around the world on a level playing field.
This conversion isn’t just for mechanics and engineers. Whether you’re restoring a vintage muscle car, buying a new lawnmower, or simply trying to understand what the numbers in a review mean, grasping this relationship is incredibly useful. It connects the classic American standard with the metric system used by most of the world, giving you a clearer picture of an engine’s size and potential power.
The Simple Math Behind Engine Size
At its heart, the conversion is straightforward. One cubic inch is equal to approximately 16.387 cubic centimeters. This number is the key to everything. So, if you want to convert a measurement from cubic inches to cc, you simply multiply the number of cubic inches by 16.387. For example, a 350 cubic inch engine, a legendary size in American V8s, converts to 350 x 16.387, which equals 5,735.45 cc. We would typically round this and call it a 5.7-liter engine.
Conversely, if you have an engine’s displacement in cubic centimeters and need to find its cubic inch equivalent, you would do the opposite: divide the number of cc by 16.387. A 1500 cc motorcycle engine, for instance, would be 1500 / 16.387, resulting in approximately 91.5 cubic inches.
A Practical Guide to Convert Cubic Inch to Cc
Let’s make this even more practical. You don’t always need a calculator for a rough estimate. Many people in garages and workshops use a simplified conversion factor of 16.39, or even just 16.4, for quick mental math. Using 16.4, that 350 cubic inch engine becomes 350 x 16.4 = 5,740 cc, which is certainly close enough for most casual comparisons and conversations.
This conversion becomes second nature with a little practice. Remembering a few common benchmarks can also help. For instance, a small 100 cc engine is roughly 6.1 cubic inches, while a massive 454 cubic inch big-block Chevy translates to a formidable 7.4 liters (7,440 cc). Having these reference points in mind makes it easier to visualize the size of an engine when you hear its displacement in the other unit.
Why This Conversion Matters in the Real World
So, why go through the trouble? Beyond simple curiosity, this knowledge is practical. When shopping for replacement parts, especially for imported machines or classic cars, specifications might be listed in the unit you’re less familiar with. Knowing the conversion ensures you order the correct pistons, cylinders, or gasket sets. It also allows you to accurately compare the engine sizes of, say, a modern European sports car (listed in liters/cc) with a classic American cruiser (listed in cubic inches).
This understanding bridges a cultural and technical gap in the automotive and power sports worlds. It empowers you to read technical documents, participate in discussions, and make informed decisions, regardless of which measurement system was originally used.
In the end, converting between cubic inches and cubic centimeters is a simple but essential tool. By remembering the core multiplier of 16.387—or a handy rounded figure like 16.4—you can easily navigate between these two common units of engine displacement. This small piece of knowledge demystifies specifications and helps you appreciate the engineering of any engine, no matter where it was built.