How to Convert Horsepower to CC

Last Updated on April 11, 2022

Horsepower is the most popular engine specification. Higher horsepower output in an engine translates into greater available power. That means faster top speeds, faster pick-up speeds, greater pulling power, better uphill capability, and more. The only downside to having an engine with higher horsepower is a correlated decrease in fuel efficiency. The other issue for truck owners and engine enthusiasts is figuring out how to convert horsepower and cc. Let’s start with the former.

Horsepower measures power output or the rate at which work is achieved. The measurement of 1 hp is equivalent to 33,000 lb-ft. A lb-ft (pound-foot) is a unit of torque representing one pound of force acting at a perpendicular distance of one foot from a pivot point.

In the 18th century, Scottish engineer James Watt first used the word horsepower to describe the output of steam engines. His terminology helped people understand steam power during a time when steam engines were replacing the power of horses. The term was later expanded to include the output power of combustion engines, turbines, electric motors and more. Today, there are different scales of horsepower, and most countries use the International System of Units for measuring horsepower.

When an engine’s horsepower is unknown, it can be measured by using an engine dynamometer (which performs a dyno test). Without a dynamometer, horsepower can be determined by using other engine specifications printed in your owner’s manual combined with running the engine at full rpm while parked and driving the car to calculate pick-up speed and determine top speed. However, this is a very complicated process.

Top engine characteristics 

To fully understand horsepower, you also have to understand torque. Torque is the rotational equivalent of linear force. Whereas liner force is the power required to move in a straight line, torque is the power required to move in a circle. Tire rotation is an example of torque. 

Furthermore, higher horsepower greatly influences top speed and pick-up speed. Torque greatly influences traction and towing capabilities. 

Engines offer different performance characteristics. A large truck and a sports car can both be equipped with engines with the same horsepower, but neither can perform in the same manner as the other. 

Torque, horsepower, and fuel efficiency are three of the top standard engine characteristics. The fourth characteristic is engine displacement. 

Engine measurement conversions

Engine displacement refers to the size of the engine measured in volume. If you dropped the engine into a pool of water, how much would the water level rise? That’s displacement. Except, with an engine, you’re measuring the interior of the engine. Thus, if you filled the entire engine with water, how much water would that be? That’s engine displacement. 

Engine displacement measures the space available inside the cylinder(s) to accommodate air-fuel mixture for burning.

Filling an engine with water is impractical and can have negative effects on the engine. Therefore, displacement is calculated by multiplying the length the pistons travel (called stroke length), the area of the cylinder (called a bore), and the total number of cylinders in the engine. The volume is expressed as:

V = π/4 x (D)² x H x N

(V = volume, D = bore diameter, H = stroke length, N = number of cylinders)

Engine displacement is usually measured in metric units. Cubic centimeters (cc) are used especially on smaller engines and liters (L) mostly in larger engines. Although, they are sometimes expressed in either cubic inches (ci) or gallons (Gal). 

Cubic centimeters can be converted into liters using the following ratio: 1 cc = 0.001 L or 1 L = 1000 cc. Cubic centimeters can be converted into cubic inches using the following ratio: 1 cc = 0.06 ci or 1 ci = 16.4 cc. Liters can be converted into gallons using the ratio 1 L = 0.22 Gal or 1 Gal = 3.8 liters.   

Remote controlled vehicles, electric bikes, go-karts, and scooters are examples of vehicles whose engines are usually expressed in terms of cubic centimeters. Several power tools are also measured in cubic centimeters. Passenger cars, trucks and motorcycles are examples of vehicles that use liters to communicate engine displacement.

Is cc or hp better?

Engine displacement is not a measurement of power, but of volume. That’s why engine displacement can’t be directly compared to horsepower. However, the size of an engine influences other characteristics like power and fuel efficiency. 

And although there is no direct correlation between an engine’s power output and its displacement, generally, engine size provides a good indicator of its power capabilities and fuel consumption.

When calculating horsepower, a factor of 16 is commonly used. For example, an engine with a displacement of 1000 cubic centimeters will have a horsepower rating of approximately 62.5.

1000 cc / 16 = 62.5 hp

Here are some other quick conversions:

Adversely, a 150-hp engine will be approximately 2,400 cubic centimeters. 

150 hp x 16 = 2,400 cc

More quick conversions:

100 hp = 1600 cc

250 hp = 4800 cc

500 hp = 8000 cc

Engine size is used as a means of classifying vehicles, and regulating them. Formula One Group, for example, although not a government body, regulates cars competing in their F1 races must be no larger than 1600 cc / 1.6 liters.

Can electric motors compete with combustion engines?

All of the information above pertains only to internal combustion engines. Engine displacement measures the space in the pistons available for air flow and electric engines don’t have pistons and they don’t require air flow.

Electric motors convert electrical energy into mechanical energy via shaft rotation. The horsepower of an electric engine can be calculated using this formula: 

HP = TN / 5250

(HP = horsepower, T = torque, N = rotational speed)

A number of factors have led to the perception that vehicles powered by electricity aren’t as powerful as machines equipped with a combustion engine. Large trucks and rockets are powered by combustion engines. Electricity powers lamps and smartphones. When car manufacturers started introducing electric-powered vehicles, it was on their small, non-performance vehicles. So, the misconception stands.

However, mining trucks have been equipped with electric engines for years and mines that have used them are putting in requests for more electric trucks. Equipped with engines rated at 800+ hp, they prove electric engines provide the power output necessary for any application. 

Ultimately, you have to decide which type of engine works best for your work or personal responsibilities, and that also means finding a vehicle to match!