In motorcycle brochures, power is sometimes written in hp, sometimes in PS, sometimes in kW; torque is in Nm or lb·ft. When the same engine appears with different figures in two sources, it is usually down to a difference in units. Reading these units correctly matters both when comparing models and when determining the licence class, because in Turkey the A1 and A2 licence limits are defined in kW. In this guide we explain what the units describe, how they are converted, and what torque and power feel like when riding. For quick conversions you can use the unit converter.
Power units: kW, hp and PS
- kW (kilowatt): the power unit of the International System of Units. This is the official unit used on registration documents, in type approval and in licence legislation.
- hp (mechanical horsepower): a unit of British and American origin. 1 hp ≈ 0.7457 kW.
- PS (metric horsepower): common in Europe, especially among German and Italian manufacturers. 1 PS ≈ 0.7355 kW. You may also see it as "CV" or "cv".
So hp and PS are very close but not the same: 1 hp ≈ 1.014 PS. A 100 hp engine is about 101 PS. The difference is small, but you should use the same unit when making comparisons.
Conversion table
| kW | hp | PS |
|---|---|---|
| 11 | 14.8 | 15.0 |
| 25 | 33.5 | 34.0 |
| 35 | 46.9 | 47.6 |
| 50 | 67.1 | 68.0 |
| 75 | 100.6 | 102.0 |
| 100 | 134.1 | 136.0 |
Formulas: kW = hp × 0.7457; hp = kW × 1.341; PS = kW × 1.3596.
Licence limits are defined in kW
In Turkey, motorcycle licence classes are defined by power, in line with Europe:
- A1: up to 125 cc and a maximum of 11 kW (about 14.8 hp).
- A2: a maximum of 35 kW (about 47 hp).
- A: unrestricted.
Examples from the catalogue: the Honda PCX 125 has 12.3 hp, about 9.2 kW, so it is in the A1 class. The Honda CB500 Hornet has 46.9 hp, exactly at the 35 kW limit; it can be ridden with an A2. The Yamaha MT-07, at 72.4 hp, about 54 kW, requires an A licence. For licence classes and age requirements see the licence guide, and for models that fit the A2 limit see the list of the cheapest A2-compatible motorcycles.
Torque: Nm and lb·ft
Torque is the turning force the engine applies to the rear wheel. Its unit is Nm (newton metre). American sources use lb·ft (pound-feet): 1 Nm ≈ 0.7376 lb·ft, 1 lb·ft ≈ 1.356 Nm.
For example, the MT-07's 68 Nm of torque is about 50 lb·ft.
Which matters more, torque or power?
They are two sides of the same coin. Power comes from torque multiplied by engine speed:
Power (kW) = Torque (Nm) × Engine speed (rpm) ÷ 9,549
This formula tells you that an engine able to rev high can produce high power even if its torque is low. An engine that produces high torque at low revs, on the other hand, feels strong the moment you open the throttle, even if its maximum power is lower.
- Strong torque at low revs: big-capacity cruisers, twin-cylinder adventure bikes. Comfortable in town and on long loaded trips; you do not need to change gear often.
- Power at high revs: four-cylinder sports bikes. Impressive on the track and open road, but most of the power is in the upper revs.
So when comparing two engines, look not only at the maximum figures but also at the revs at which these values are reached. Manufacturer brochures usually give these values in the form "power / revs", together with the engine speed.
Power-to-weight ratio: the real indicator of performance
Of two engines with the same power, the lighter one is more agile and accelerates faster. For a simple comparison, divide power by weight:
| Model | Power | Weight | hp/kg |
|---|---|---|---|
| KTM 390 Duke | 44.3 hp | 165 kg | 0.27 |
| Honda CB500 Hornet | 46.9 hp | 192 kg | 0.24 |
| Yamaha MT-07 | 72.4 hp | 183 kg | 0.40 |
| Yamaha MT-09 | 117.3 hp | 193 kg | 0.61 |
The weight figures are those given by the manufacturer; some manufacturers give dry (without fluids) weight and some give ready-to-ride (full tank) weight, which affects the comparison by a few kilograms. To see models side by side you can use the comparison page.
Manufacturer figure and rear-wheel power
The power in the brochure is the value measured at the engine's crankshaft. The power measured at the rear wheel on a dynamometer comes out somewhat lower because of transmission, chain and tyre losses. If you see a forum comment saying "it measured lower on the dyno", this is usually why. When comparing, always use the same type of measurement; all values in the catalogue are manufacturer data.
Other units you often come across
- bar and psi: used for tyre pressure. 1 bar ≈ 14.5 psi. For example, 2.5 bar ≈ 36 psi.
- L/100 km and km/L: consumption units. 4 L/100 km = 25 km/L.
- mph: miles per hour. 100 km/h ≈ 62 mph.
What to watch when reading a brochure
Looking only at the power figure when comparing models can be misleading. There are cases where the same engine is sold in different markets with different power values: some models have versions restricted to 35 kW that suit the A2 licence. These versions usually come with an electronic or mechanical restriction, and the power value written on the registration document is what is decisive for the licence. If you plan to ride a motorcycle on an A2 licence, make sure the version you buy is registered on the registration document as 35 kW or less.
In brochures, power is also sometimes given as "maximum" and sometimes as "nominal"; on some electric motorcycles there is a big difference between continuous power and peak power. For electric models it matters which value is used as the basis for licence and classification; see the electric motorcycle guide on this. Finally, the power, torque, weight and consumption values on our model pages are manufacturer data and are shown in the same unit; making your comparison there removes any unit confusion.
Torque curve and daily use
Even if you see a single torque figure in the manufacturer brochure, what really determines an engine's character is how the torque is spread across the rev range. Engines that offer high torque across a wide rev range need fewer gear changes in town and on long loaded trips, and feel safer when overtaking. Engines that produce high power in a narrow range expect the rider to stay in the right gear and at high revs. To feel this on a test ride, open the throttle from low revs in the same gear and notice how the engine pulls.
In short, the power figure tells you how fast an engine can go, while the torque curve tells you how easy it is to ride day to day; assess the two together.
Conclusion
The official unit is kW; hp and PS are close to each other but not the same. When checking licence limits, convert power to kW, use the same unit when comparing models, and look at the revs at which torque and power arrive. To find out which power range suits you, you can try the motorcycle finder.
Frequently asked questions
How many horsepower is 1 kW?
1 kW is about 1.341 hp (mechanical horsepower) or 1.36 PS (metric horsepower).
Up to how many horsepower can an A2 licence ride?
The A2 limit is 35 kW; that is about 47 hp or 47.6 PS.
Are hp and PS the same thing?
No, but they are very close. 1 hp is about 1.014 PS. A 100 hp engine has about 101 PS.
What does Nm mean?
Newton metre is the unit of torque. It shows the turning force the engine applies to the wheel. The torque available at high and low revs determines how strong the engine feels when accelerating.