How to Convert CC to HP?

As any bike enthusiast knows, the power of the engine is what makes the ride. But have you ever wondered how that power is measured? 

Sure, you may know the basic specs of your bike’s engine – the displacement, or CC, and the horsepower, or HP – but how do these two numbers relate to one another? And how to convert CC to HP?

Converting CC to HP in a motorcycle engine is not a straightforward process, as many factors can affect the power output. 

However, a general rule of thumb is that for every 15 CC, you can expect approximately 1 HP. It is important to keep in mind that this estimate can vary depending on the specific engine and its components.

The most convenient way to convert/calculate CC to HP is to use our calculator below.

How to Convert CC to HP?

To convert cc to hp for a motorcycle engine, you need to use the general rule that for every 15 ccs, there is one horsepower.

So, to convert cc to hp, you need to divide the cc value by 15. 

Here’s the formula:

hp = cc/15

For example, if you have a 200 cc motorcycle engine, you would divide 200 by 15, which gives you 13.33 hp.

Conversely, if you have the horsepower value and want to find out the cc of the motorcycle engine, you need to multiply the horsepower value by 15. For example, if you have a 10 hp motorcycle engine, you would multiply 10 by 15, which gives you 150 cc.

What is CC?

CC, or cubic centimeters, is a measure of the engine displacement. It refers to the volume of air and fuel mixture that the engine can draw in during one cycle of the piston. In simpler terms, it measures the size of the engine. 

For example, a 250cc motorcycle engine has a displacement of 250 cubic centimeters, meaning that it can draw in and combust 250 cubic centimeters of air and fuel mixture in one piston cycle. This usually correlates to the power output of the engine, with larger CC engines generally providing more power than smaller CC engines.

How to Calculate Engine Capacity in CC?

To calculate the engine capacity of an internal combustion engine, also known as the displacement, in cubic centimeters (cc), you need to know the bore (diameter) and stroke (length of travel) of the engine’s pistons, as well as the number of cylinders the engine has.

The formula to calculate the engine capacity in cc is:

Engine Capacity = (π/4) x bore² x stroke x number of cylinders


  • π is the mathematical constant pi (approximately equal to 3.14)
  • bore is the diameter of the piston 
  • stroke is the length of travel of the piston 
  • number of cylinders is the number of cylinders in the engine

Let’s take an example to understand how to use this formula.

Consider an engine with a bore of 8.6 cm and a stroke of 10 cm, and four cylinders.

Engine Capacity = (3.14/4) x (8.6 x 8.6) x 10 x 4

Engine Capacity= 675.53 CC

Therefore, the engine capacity of this four-cylinder engine is 675.53 CC.

Why Does Engine CC Matter?

Engine CC is an important specification to remember whilst deciding on a motorcycle. The following are the reasons why engine CC topics:

Power output: Generally, the higher the engine’s CC, the extra power the engine can produce. This is due to the fact a larger engine can burn more fuel and create extra combustion, ensuing in more power being produced. So, in case you are seeking out a powerful engine, you can want to pick out one with a higher CC.

Fuel economic system: The size of the engine can affect the fuel financial system as properly. A smaller engine with decreased CC can be greater in fuel efficiency than a bigger engine with higher CC.

Speed: A better engine CC also can affect the rate of an automobile. As mentioned earlier, a larger engine can produce more power, which could translate to an increased pace.

Weight: It can have an impact on the weight of the motorcycle. A larger CC engine usually weighs more than a smaller one, which may affect the overall weight distribution of the bike. This can affect coping with, stability, and even fuel the economic system.

Cost: Larger CC engines tend to be extra steeply-priced than smaller engines. This is due to the fact they require greater substances and more complicated production methods to manufacture. Additionally, large engines could have higher maintenance charges.

What is HP?

HP usually stands for “horsepower,” which is a unit of power used to measure the rate at which work is done. Horsepower is often used to describe the power output of an internal combustion engine.

One horsepower is equal to the energy needed to lift 550 pounds (250 kilograms) one foot (0.3 m) or about 746 watts per second.

For a motorcycle engine, horsepower refers to the amount of work an engine can do in time and is a function of various factors such as engine size, configuration, and performance.

A general increase in horsepower means that the engine can produce more power and provide better acceleration and top acceleration.

How to Calculate Engine HP (horsepower)?

You can use the following method to calculate engine power (HP).

HP = (torque x rpm) / 5252


  • The HP engine has horsepower
  • Torque is engine torque in pound-feet (lb-ft).
  • RPM is engine speed in revolutions per minute

Here is an example:

Let’s say you have a bike engine that produces 300 lb-ft of torque at 5000 RPM. If you wanted to calculate its horsepower you would use this formula:

HP = (300 lb-ft x 5000 rpm) / 5252

The calculation can be simplified to:

HP = 285.88

So, the output of this engine is estimated to be 286 hp.

Why Does Engine HP Matter?

An engine’s horsepower (HP) is an essential metric this is often used to decide an engine’s energy output. The following are a few reasons why engine horsepower is essential.

Acceleration: The more horsepower an engine has, the quicker it may run. This is due to the fact horsepower is the quantity of work an engine can do in a given amount of time. The greater horsepower an engine has, the greater work it could do, and the quicker it hurries up.

Towing and Hauling: If you propose to tow or haul heavy loads, you want an engine with enough horsepower to handle the greater load. More horsepower can help your engine pull or push its load quicker, improving efficiency and reducing strain on the engine.

Maximum Speed: Horsepower performs an important role in figuring out the most velocity of an engine. Engines with extra horsepower can produce more strength, allowing for higher speeds. Conversely, engines with decreased horsepower will warfare to reach maximum pace even under excellent conditions.

Fuel Economy: Engines with more horsepower tend to have lower fuel economy because they require extra fuel to generate strength. However, modern engine technology lets in for greater effective engines which can be also extra fuel-green.


Final Thoughts!

The CC to HP conversion is a fascinating topic that has intrigued motorcycle enthusiasts for decades. 

By understanding the relationship between engine displacement and horsepower, riders can make informed decisions when choosing a new bike or upgrading their current ride. 

About David Riedel

I am David Riedel founder of Bikerwhizz, I'm a technician at Keystone Harley Davidson with more than 10 years of industry experience. I’m here to help you solve motorbike problems, customizations, tweaks, and easy fixes to enjoy your rides more.

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