CC to HP Conversion Charts [Small and Big Engines]


How many cc do you need for one horsepower?

The general rule is that every 5-6 cc generates 1 HP for hypercars and high-performance powersport vehicles. When it comes to average cars and vehicles, you can expect to get 1 HP from every 7 to 20 cc. On the other end of the spectrum, you can find large utility engines that deliver 1 HP for every 25-80cc.

If you want to drill into the details, this post is for you.

We at PowerSportsGuide have compiled the most common cc/HP ratios for many different engines into one chart!

Are CC and HP the Same?

Although CC and HP figures are not the same, there’s a loose relationship between these specifications. The CC (means: cubic centimeters) refers to the engine’s displacement, which is the size of the combustion chambers. In contrast, the HP (horsepower) references the engine’s power output.

In other words, the CC number shows how big the engine is, while the HP tells how powerful it is.

It’s safe to say that there’s a correlation between these figures, but contrary to popular belief, a larger displacement doesn’t necessarily mean higher HP ratings.

This is because engine power doesn’t solely depend on its displacement but on many other features as well.

Let’s get into details and talk about these in detail!

Factors that Affect the CC/HP Ratio

Many different factors affect an engine’s cc/HP ratio, but the major ones are as follows:

  • Engine stroke
  • Type of engine (diesel vs. gasoline)
  • Cooling system
  • Numbers and dimensions of the cylinders
  • Aspiration (naturally-aspirated vs. super or turbocharged)
  • Materials, tolerances, and compression ratio

One of the most important factors is the type of engine. 2-strokes usually have a better cc/HP ratio than 4-strokes due to their design.

Liquid-cooled engines are also more efficient than their air-cooled brothers, so they crank out more HP with the same displacement.

Another key factor is the number and the dimensions of the cylinders. The general rule is that the more cylinder the engine has, the more power it can deliver.

Engine aspiration also has a major effect on performance. Supercharged and turbocharged engines burn much more fuel, delivering more power than naturally-aspirated power sources.

There are also many important factors like engine materials, design, tolerances, and compression ratio that significantly affect the HP per cc ratio.

The bore and stroke of the engine are no less important. The smaller the cylinder bore, the longer stroke the engine has. These long-stroke engines generate more torque but have worse HP to cc ratios.

“Big-bore” engines have large-diameter pistons combined with short strokes. Since the pistons in these engines can move much faster, they can deliver much more power.

This is why 600cc and 1000cc sportbikes with 4-cylinder, in-line, big-bore engines have very good cc/HP ratios.

For example, the Kawasaki Ninja H2 motorcycle is powered by a supercharged, 992cc in-line engine rated at 310 HP (3.2 cc = 1 HP). Since V-twin engines deliver much less power, an average 1000cc Harley produces about 70 HP (14 cc = 1 HP).

Regarding 4-wheelers, a 1500cc racing car engine can crank out up to 400 HP, which means 3.75 cc delivers 1 HP. In contrast, a 1500cc farm tractor puts out about 20 HP, meaning that 75cc can only produce 1 HP.

Consequently, there is a huge difference in the HP ratings of engines with the same displacement!

How Much CC is Equal to 1 HP?

For your convenience, we’ve done the research and compiled the cc/HP ratings of the most common engine categories into one list:

  • 10-30cc RC engines: 5-10 cc/HP
  • Jet skis: 5-10 cc/HP
  • Motorcycles: 5-15 cc/HP
  • Snowmobiles: 5-22 cc/HP
  • Cars: 7-15 cc/HP
  • Small industrial engines: 10-20 cc/HP
  • ATVs: 13-18 cc/HP
  • Outboard engines: 15-25 cc/HP
  • Lawnmowers and snow blowers: 25-40 cc/HP
  • Utility tractors: 40-80 cc/HP

CC to HP Conversion Charts

Here are some more detailed lists with the most common engine sizes and categories:

CC to HP Conversion for Small Engines

Displ.HPCategorycc/HP
10cc2RC vehicles5
20cc2.5-3RC vehicles7-8
30cc3-4RC vehicles8-10
30cc2-3Chainsaw10-15
40cc2.5-3Chainsaw13-16
50cc3-4Chainsaw13-17
50cc3-9Motorcycle6-17
60cc3.5-4Chainsaw25-17
70cc5-6Chainsaw12-14
80cc6-10Motorcycle8-13
80cc6-7Chainsaw11-13
90cc6.5-8Chainsaw11-14
100cc7-9Chainsaw11-14
100cc7-12Motorcycles8-14
120cc8-9Chainsaw13-15
125cc10-15Motorcycles8-13
125cc3-5Lawnmowers25-42
125cc4-5Outboards25-30
150cc4-5Lawnmowers30-40
150cc10Snowmobiles15
150cc10-11Go-Karts14-15
150cc15-25Motorcycles6-10
150cc5-6Outboards25-30
200cc6-7Go Karts29
200cc6-7Snowblowers29-33
200cc9Snowmobiles22
200cc8-10Outboards20-25
200cc15-25Motorcycles8-13
250cc20-40Motorcycles6-13
250cc15-35ATVs7-17
300cc9-10Snowblowers30-33
300cc30-40Motorcycles8-10
350cc10-11Snowblower32-35
350cc35-45Motorcycles8-10
350cc20Outboards18
400cc11-13Snowblowers31-36
400cc40-55Motorcycles7-10

CC to HP Conversion for Large Engines

Displ.HPCategorycc/HP
500cc25Outboards20
500cc17-20Riding mowers25-29
500cc30-40ATVs13-17
500cc45-60Motorcycles8-11
600cc18-22Riding mowers27-33
600cc40-45ATVs13-15
600cc55-130Motorcycles5-11
600cc120-130Snowmobiles5
700cc20-24Riding mowers39-35
700cc60-150Motorcycles5-12
700cc40-50ATVs14-18
750cc24-26Riding mowers29-31
750cc50-55ATVs14-15
750cc65-150Motorcycles5-12
800cc50-65UTVs12-16
800cc54-60Cars13-15
800cc65-150Motorcycles5-12
800cc160-170Snowmobiles5
900cc75-90UTVs10-12
900cc60-110Cars8-15
900cc60-90Jet skis10-15
900cc65-150Motorcycles6-14
900cc160-170Snowmobiles5-6
1000cc60-170UTVs6-17
1000cc65-140Cars7-15
1000cc50-70Outboards14-20
1000cc90-120Jet skis8-11
1000cc80-220Motorcycles5-13
1000cc200-210Snowmobiles5
1500cc18-25Tractors60-86
1500cc100-200Cars8-15
1500cc75-115Outboards13-20
1500cc160-310Jet skis5-9
1800cc30-45Tractors40-60
1800cc75-115Outboards16-24
1800cc140-240Cars8-13
1800cc180-250Jet skis7-10
2000cc30-50Tractors40-67
2000cc75-115Outboards17-27
2000cc150-300Cars7-13
3000cc40-60Tractors50-75
3000cc115-150Outboards20-26
3000cc250-400+Cars8-12

Disclaimer: These charts are for information purposes only!

Note that these are just hard numbers, about average stock engines. If you do extensive research, you can likely find some engines that do not fit within these ballpark figures.

How to Convert CC to HP

Although there’s no exact formula for converting engine CC to HP, here are some general calculation rules that work in most cases:

  • High-performance powersport vehicles and hypercars: divide the CC by 5-6 to get the HP
  • Average cars and powersport vehicles: divide the CC by 7-20 to get the HP
  • Outboard engines: divide the CC by 15-25 to get the HP
  • Small industrial engines: divide the CC by 10-20 to get the HP
  • Lawnmowers and snow blowers: divide the CC by 25-40 to get the HP
  • Utility tractors: divide the CC by 40-80 to get the HP

Unfortunately, it’s impossible to give more accurate ranges due to the large differences in engine features.

FAQs – How to Change CC to HP

As a takeaway, we’ve answered the most common questions on the topic.

Are CC and HP the Same?

CC and HP are completely different specifications; CC (cubic centimeters) refers to the engine’s displacement while HP (horsepower) tells us how powerful the engine is.

How Many CC Produces One Horsepower?

When it comes to internal combustion engines, 5-80cc can produce one horsepower. High-performance, big-bore in-line engines have a cc per HP ratio of 5-6. You can find these power sources in sportbikes, hypercars, turbocharged snowmobiles, and jet skis.

You can also expect to get about 7-20 cc per HP ratio in most cars and the average powersport vehicles with naturally-aspirated engines.

It’s safe to say that the worse cc/HP ratios are produced by 4-stroke utility engines; lawnmowers have about 25-40 cc per HP, while larger tractors have only 40-80 cc per HP.

How to Convert CC to HP

Since engine features differ from one model to the next, there’s no exact conversion from CC to HP.

However, if you are looking for some hard numbers, you can’t go wrong by using these CC to HP formulas:

  • High-performance powersport vehicles and hypercars: divide the CC by 5-6 to get the HP
  • Average cars and powersport vehicles: divide the CC by 7-20 to get the HP
  • Outboard engines: divide the CC by 15-25 to get the HP
  • Small industrial engines: divide the CC by 10-20 to get the HP
  • Lawnmowers and snow blowers: divide the CC by 25-40 to get the HP
  • Utility tractors: divide the CC by 40-80 to get the HP

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