The honest version of the most-asked engine question: displacement does not convert to power, so here is the range it implies, and the units that genuinely do convert.
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There is no cc-to-hp conversion, so this asks what kind of engine it is. Without that, the honest answer is a range sixteen times wide.
2,000 cc, as a naturally aspirated petrol, modern or sporting
160–230 hp
119–172 kW · 162–233 PS · a range, because the question has no single answer
The same 2,000 cc, in every kind of engine
One displacement, ordered by how hard the engine is worked
Engine type
hp per litre
This engine
Why
Small utility, generator or pump
20–45
40–90 hp
Built for hours of running and low cost, not for output. A 400 cc generator engine may make 10 hp.
Turbodiesel, road car
45–80
90–160 hp
Limited by combustion speed and peak cylinder pressure. Makes its case on torque and fuel, not on this number.
Naturally aspirated petrol, economy
55–80
110–160 hp
The classic family-car figure, and the source of the "about 70 per litre" rule of thumb.
Naturally aspirated petrol, modern or sporting
80–115
160–230 hp
Direct injection and variable valve timing moved this up substantially in twenty years.
Turbocharged petrol, road car
100–170
200–340 hp
Forced induction breaks the link to displacement entirely: the engine swallows more air than its volume.
Motorcycle, high-revving
100–180
200–360 hp
Power is torque times speed, so revs buy output. Small engines turning 12 000 rpm do very well here.
Litre-class superbike
180–220
360–440 hp
A 1000 cc engine making 200 hp — the same displacement as a family car making 130.
Modern racing, forced induction
220–320
440–640 hp
Extreme boost, extreme revs and a rebuild schedule. Not a road engine in any sense.
Top to bottom that is 40 to 640 hp from the same 2,000 cc — a factor of 16. Displacement sets how much air the engine can draw in one cycle; everything else about the output is how many cycles a second, how much pressure that air arrives at, and how completely it burns. None of that is in the displacement figure.
Working backwards from a real engine
Specific output75.0 hp/Lin the range for turbodiesel, road car
Torque at 6000 rpm131.3 lb-ft178.0 N·m
Where the two curves cross5,252 rpm33 000 ÷ 2π, a property of the units
Specific output is the figure worth comparing, because it removes the displacement and leaves the engineering. And torque is not an alternative to power — power is torque times engine speed, which is why the two lines on every dyno chart cross at 5252 rpm and only there. That number is 33,000 divided by 2π: it comes from the definition of horsepower, not from anything the engine is doing.
The parts that do convert
Displacement, exactly
Unit
Value
Note
cubic centimetre (cc)
2,000.0
The same thing as a millilitre. How motorcycles and small engines are sized.
cubic inch (cu in)
122.0
Exactly 16.387064 cc. American V8s are still quoted this way.
litre (L)
2.000
How cars are sized nearly everywhere. A 2.0 is 2000 cc.
Power, and the three horsepowers
Unit
Value
Note
watt (W)
111,855
The SI unit. Everything else here is defined against it.
metric horsepower (PS)
152.08
Exactly 75 kgf·m/s. Also written CV, pk or hk. The figure on most European brochures.
mechanical horsepower (hp)
150.00
Exactly 550 ft·lbf/s. The British and American figure, 1.4% larger than PS.
electrical horsepower (hp (electrical))
149.94
Exactly 746 W, defined for motor ratings rather than measured.
kilowatt (kW)
111.85
What type approval and most registration documents use.
Both ladders are exact — a cubic inch is exactly 2.54³ cc and every horsepower here is a defined number of watts. The one to watch is the pair in the middle: PS is 1.4% smaller than hp, so a German brochure quoting 300 PS is 296 hp, and a figure carried across without conversion is wrong by about the amount manufacturers spend a great deal of money arguing over.
What this converter covers
Eight engine classes with real specific-output ranges, exact cc, litre and cubic-inch conversions, all three horsepowers, and the torque link through rpm.
What displacement can and cannot tell you about power
Specific output ranges for utility, diesel, naturally aspirated, turbo, motorcycle and racing engines
Cubic centimetres, litres and cubic inches, exactly
Mechanical horsepower, metric PS and the electrical horsepower
Power against torque, and why the curves cross at 5252 rpm
No conversion exists Eight engine classes Specific output cc · L · cu in · hp · PS · kW
Free, no signup — exact by definition, not an estimate.
Updated 8 September 2026
At a glance
Formula shown
hp = torque in lb-ft × rpm ÷ 5252 · specific output = hp ÷ litres
Scenario support
1000 cc is 20 hp in a generator and 220 in a superbike · 100 PS is 98.6 hp
Educational estimate
Planning support from the values you enter — not professional advice.
Why there is no conversion
“How many horsepower is 1000 cc” is one of the most-searched engine questions there is, and the honest answer is that the question does not have one.
Displacement is a volume: the total swept by the pistons in one cycle. Power is a rate of doing work. No factor connects them, in the same way no factor connects the size of a fuel tank to how fast a car goes.
What displacement actually sets is how much air the engine can draw in per cycle. Power then depends on three further things, none of which appears in the displacement figure:
How many cycles per second. Power is torque times engine speed, so an engine that revs to 14,000 rpm makes far more of it than an identical one limited to 5,000.
At what pressure the air arrives. A turbocharger forces in more air than the cylinder’s volume would hold unaided, which breaks the link to displacement outright.
How completely it burns, and what it costs. Compression ratio, fuel, valve timing and management all move the number — and so does how long the engine is expected to survive, which is why a race engine and a generator engine of the same size are not comparable objects.
What can honestly be said
The useful answer is a range, once you say what kind of engine it is. Here is the same one litre, eight ways:
One litre of displacement, by engine type
Engine type
hp per litre
So 1000 cc is
Utility, generator, pump
20–45
20–45 hp
Turbodiesel road car
45–80
45–80 hp
Naturally aspirated petrol, economy
55–80
55–80 hp
Naturally aspirated petrol, modern
80–115
80–115 hp
Turbocharged petrol road car
100–170
100–170 hp
Litre-class superbike
180–220
180–220 hp
Modern racing, forced induction
220–320
220–320 hp
Top to bottom that is 20 hp to 320 hp from the same displacement, a factor of sixteen. Any single number offered as “the” answer is picking one row of that table without saying which.
The rule of thumb people half-remember — about 70 hp per litre — is the fourth row, an ordinary naturally aspirated petrol engine from roughly the 1990s. It was a decent approximation for the cars around at the time and has been steadily overtaken since; a modern turbo engine makes twice it.
Turn the arithmetic round and it becomes genuinely useful. Divide a real engine’s power by its displacement and you get specific output, which strips out the size and leaves the engineering — and which tells you immediately whether an engine is relaxed, ordinary or highly strung.
Three horsepowers
The part that is a unit conversion has its own trap, and it is worth about one and a half per cent.
The three horsepowers in use
Name
Definition
Watts
Metric (PS, CV, pk)
75 kgf·m/s
735.49875
Mechanical (hp, bhp)
550 ft·lbf/s
745.6999
Electrical
defined outright
746 exactly
Continental European brochures quote PS. British and American ones quote mechanical horsepower. The two differ by 1.4%, so a car sold as 300 PS is 296 hp, and a figure carried across without conversion is out by about the margin manufacturers spend enormous sums competing over.
Type approval, meanwhile, is in kilowatts, which is why a registration document and a sales brochure for the same car often carry two unfamiliar numbers. 300 PS is 221 kW is 296 hp — one engine, three correct figures.
The electrical horsepower is the odd one out: exactly 746 watts, defined rather than derived, and used for motor ratings rather than for engines. It differs from the mechanical horsepower by only 0.04%, which is why nobody notices it, and it is in the calculator above for completeness rather than because it matters here.
Torque, power and the 5252
Torque and power get discussed as rivals, and they are not two things. One is defined in terms of the other.
Power is torque times engine speed. Torque is the twist the crankshaft is producing at an instant; power is how fast that twist is doing work. An engine making 400 lb-ft at 2,000 rpm and one making 200 lb-ft at 4,000 rpm are producing the same power.
Which is where the famous number comes in. Written in the customary units, hp = lb-ft × rpm ÷ 5252, so the two curves on any dyno chart cross at 5252 rpm — always, on every engine ever built.
That is not a fact about engines. It is 33,000 divided by 2π, and 33,000 is in there because James Watt defined a horsepower as 33,000 foot-pounds per minute. The crossover is a property of the units, and in metric it does not exist at all: kW = N·m × rpm ÷ 9549, and 9549 is not an engine speed anyone reaches.
What is genuinely true underneath the argument is that torque at the wheels decides acceleration, and gearing multiplies torque while dividing speed. So an engine that makes its power high in the rev range delivers the same shove through a lower gear. Power is the figure that survives gearing; torque alone is not comparable between engines without saying at what speed.
Why the same engine gets two ratings
One last reason no formula could produce a power figure: the figure is the result of a test, and the test has options.
Gross against net. American figures before the early 1970s were measured with the engine stripped of alternator, water pump, air cleaner and exhaust. Net figures include them. The change of standard alone knocked twenty per cent off published outputs in a single model year, with no engineering change whatever — which is why old and new figures for the same engine are not comparable.
Ambient correction. Air density varies with temperature, pressure and humidity, so test standards correct the measured figure to reference conditions. Different standards use different reference conditions, and the correction is worth a few per cent.
Where it is measured. At the crankshaft or at the wheels. A chassis dyno reads perhaps 12 to 18 per cent lower on a passenger car because the transmission and driveline absorb the difference, and that figure is not fixed either.
So “how much power does it make” has an answer, but it is a measurement with a procedure attached rather than a number you can compute. Which is the same conclusion the top of this page reached from the other direction — and the reason the calculator above gives you a range and asks you what kind of engine you meant.
Related calculators
Other power, torque and automotive tools:
PowerWatts, kilowatts, horsepower and BTU per hour — with mechanical and metric horsepower listed apart, since they differ by 1.4% under one word.
TorqueNewton-metres, pound-feet, pound-inches and kgf·m — with inch-pounds and foot-pounds named apart, since they differ by twelve.
Fuel Economympg, L/100 km and km/L — US and UK mpg kept apart, and the reciprocal explained, since a better car has a LOWER L/100 km.
VolumeLitres, gallons, pints and cubic units — with US and imperial named apart, because a UK gallon is 20% larger than a US one.
Speedmph, km/h, m/s, ft/s and knots on exact factors, with the nautical mile behind the knot explained rather than assumed.
kVA to kWApparent, real and reactive power with the line current for single and three-phase supplies — power factor required, because kVA and kW are different quantities.
The first two are why a power figure is a test result rather than a calculation, and why the same engine legitimately carries different numbers in different markets. The third is where the three horsepowers get their definitions.
SAE J1349 — Engine Power Test Code, Spark Ignition and Compression IgnitionSAE International · verified 2026-09-08 · That a power figure is the result of a specified test procedure with defined ambient corrections and installed accessories, rather than a property derivable from the engine’s dimensions — which is why two ratings of the same engine can differ legitimately
Regulation (EC) No 715/2007 on type approval of motor vehiclesOfficial Journal of the European Union · verified 2026-09-08 · The European type-approval framework under which engine power is declared in kilowatts, and the reason a registration document and a sales brochure for the same car can carry different-looking numbers
SI Brochure, 9th edition — the wattBureau International des Poids et Mesures · verified 2026-09-08 · The watt as the SI unit of power, against which the mechanical horsepower of 550 ft·lbf/s, the metric horsepower of 75 kgf·m/s and the exactly-746-watt electrical horsepower are each defined
Conversion note
The output ranges here are representative of ordinary production engines and are not predictions about any particular one. Specific output depends on the induction system, valve timing, compression ratio, fuel, ignition and engine management, the rev limit, the exhaust, and how long the manufacturer expects the engine to last — an engine tuned for two hundred thousand kilometres and one tuned for a race weekend can share a displacement and differ by a factor of three. Quoted power figures also depend on the test standard, on whether the engine was measured with its own accessories fitted, and on ambient correction factors, so two honest ratings of the same engine can differ by several per cent. Nothing here estimates the output of a modified engine, predicts the effect of a change, or substitutes for a dynamometer run. Vehicle performance depends on far more than engine power — mass, gearing, aerodynamics, traction and transmission losses among them — and power alone predicts very little about it.
Published the CC to HP Converter, whose central product is a refusal: displacement is a volume and power is a rate of doing work, and no factor connects them.
Gives the honest alternative instead -- a range, once the kind of engine is named -- across eight classes from small utility engines at 20 hp per litre to modern forced-induction racing at over 300.
Shows the width of that answer: the same 1000 cc is 20 hp in a generator and 320 in a racing engine, a factor of sixteen, so any single number offered as THE answer has silently picked one row.
Names what displacement actually sets -- how much air the engine draws per cycle -- and the three things it does not: engine speed, induction pressure, and how completely the charge burns.
Records that the half-remembered 'about 70 hp per litre' rule is one specific row, an ordinary naturally aspirated petrol engine of the 1990s, and that a modern turbo engine makes twice it.
Converts what genuinely does convert, exactly: cubic centimetres, litres and cubic inches, and mechanical horsepower, metric PS, the electrical horsepower and kilowatts.
Flags the 1.4 per cent gap between mechanical horsepower and metric PS, which is why a 300 PS car is 296 hp and 221 kW -- one engine, three correct figures.
Relates torque to power through engine speed and explains that 5252 is 33000 divided by 2 pi, a property of the customary units rather than a fact about engines, with no equivalent crossover in metric.
Explains why the same engine legitimately carries different ratings: gross against net, ambient correction, and crankshaft against wheels.
Verified by 66 automated cases, asserting that the displacement-to-power function returns null and that no export offers that answer under another name, that the full class spread exceeds a factor of ten, that the three horsepowers match their definitions of 550 ft-lbf/s, 75 kgf-m/s and exactly 746 W, and that power and torque are numerically equal exactly at 33000/2pi rpm.
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