If you look for a horsepower figure on a German registration certificate, you will not find one. The engine power is listed in kilowatts only – in field P.2. This article shows exactly where to find it, what the number after the slash means, how to convert the value to metric horsepower (PS) or imperial horsepower (hp) and why electric cars often show far fewer kW than their brochure.
The power is in field P.2 – in kilowatts
Since October 2005 the German vehicle registration document has officially been called Zulassungsbescheinigung Teil I (registration certificate part I; colloquially still Fahrzeugschein). Its fields carry letter-number codes that are the same across the EU. Engine power is in field P.2, which contains the rated power of the engine in kilowatts.
Directly after it, separated by a slash, comes the value of field P.4: the rated engine speed, i.e. the revolutions per minute at which that power is reached. An entry such as “110/5500” therefore means 110 kW rated power at 5,500 rpm. For motorcycles and other category L vehicles you will sometimes see only a dash instead of the speed, for example “75/-”, because the certificate of conformity of these vehicles does not include a rated engine speed.
Next to it you find field P.1 with the engine displacement in cubic centimetres and field P.3 with the fuel type or power source. There is no PS or hp figure anywhere on the certificate.
| Field | Content | Example |
|---|---|---|
| P.1 | Displacement in cm³ | 1498 |
| P.2 | Rated power in kW | 110 |
| P.4 | Rated engine speed in min⁻¹ (after the slash) | 5500 |
| P.3 | Fuel type or power source | Petrol |
How to convert the kW on the certificate to PS
To convert, divide the kW value by 0.73549875 – or, which amounts to the same, multiply it by 1.35962:
An example: if field P.2 says 110, the engine delivers 110 ÷ 0.73549875 = 149.56 PS. Brochures and listings turn that into “150 PS”, because the PS figure is usually rounded to a whole number. For mental arithmetic the rule of thumb kW × 1.36 is good enough: it is only about 0.03% off the exact value.
In the other direction you get from a PS figure back to the value on the certificate by multiplying by 0.73549875: 150 PS × 0.73549875 = 110.32 kW, so 110 kW on the certificate. The table below shows typical values that frequently appear on car registration certificates:
| kW (field P.2) | PS exact | PS rounded |
|---|---|---|
| 55 | 74.78 | 75 |
| 66 | 89.74 | 90 |
| 74 | 100.61 | 101 |
| 81 | 110.13 | 110 |
| 85 | 115.57 | 116 |
| 96 | 130.52 | 131 |
| 110 | 149.56 | 150 |
| 140 | 190.35 | 190 |
| 180 | 244.73 | 245 |
All values from 1 to 500 kW, with hp and rounded PS, are in the table of the kW to PS and hp calculator. There you can also enter any value, such as the power from your own registration certificate.
Why the certificate has no PS
The fact that the certificate shows kilowatts only has a legal reason. Germany's Units and Time Act requires quantities in official and commercial use to be stated in legal units. Which units those are is set by the Units Ordinance – for power it is the watt and therefore also the kilowatt. The metric horsepower is not among them. It has not been a legal unit in Germany since 1978.
It has not disappeared entirely, though. PS remains permitted as a supplementary indication next to the legal unit. That is why brochures, road tests and listings usually say “110 kW (150 PS)”: the kW value is authoritative, the PS figure is a translation for everyone who still thinks in horsepower.
Where the odd number 0.73549875 comes from
The horsepower dates back to the age of steam engines. It was meant to make the output of a machine comparable to the work of horses. 1 PS is defined as the power needed to lift a mass of 75 kilograms by one metre in one second, i.e. 75 kilogram-force metres per second. With standard gravity of 9.80665 m/s² this gives:
The value is exact, not rounded. It yields the two conversion factors 1 PS = 0.73549875 kW and 1 kW = 1.35962 PS. Exactly this value already appears in the European units directive of 1971.
Careful with English-language spec sheets: the horsepower (hp) used there is defined differently, as 550 foot-pounds per second. That is 745.7 W, about 1.4% more than one PS. 150 hp therefore equal 152.1 PS or 111.9 kW. The calculator converts hp as well – just switch the input to “hp”.
Special case electric car: continuous power on the certificate
For electric cars, field P.2 does not show the peak power advertised in brochures. It contains the maximum 30-minute power, i.e. the power the electric drive can sustain continuously for half an hour. This is what the guide of the German Federal Motor Transport Authority on filling in the registration certificate requires; the measurement follows UN Regulation No. 85.
Because electric motors can briefly deliver much more than they can sustain, the number on the certificate is often considerably lower than the advertised one. That is not a mistake by the registration office. Why this is so and how to compare the two figures correctly is explained in Electric Car Power: Rated Power vs. Peak Power.
What the kW figure matters for – and what not
- Motorcycle licence: Classes A1 and A2 have fixed power limits of 11 and 35 kW. Whether a motorcycle qualifies depends on the value in the vehicle documents. Details in Motorcycle Licence A1, A2, A: Which kW Limits Apply in Germany?
- Vehicle tax: Power plays no role here. For cars first registered from 1 July 2009, displacement and CO₂ emissions count, for motorcycles displacement, and for battery electric cars, once the exemption ends, the permissible total weight. Work out your tax with the vehicle tax calculator.
- Buying a car: Compare the PS figure in the listing with the kW value in field P.2. If the converted value differs noticeably, it is worth asking – for combustion cars perhaps because of a different engine variant, for electric cars usually because of the difference between peak and continuous power.
Summary
- The power is in field P.2 of the registration certificate, always in kW; the rated engine speed from P.4 follows after the slash.
- PS = kW ÷ 0.73549875, rule of thumb kW × 1.36. Example: 110 kW = 149.56 PS ≈ 150 PS.
- PS has not been a legal unit since 1978 but is allowed as a supplementary indication.
- For electric cars, P.2 shows the maximum 30-minute power, not the peak power.
As of October 2026. Sources: guide of the Federal Motor Transport Authority on filling in the registration certificate, Units and Time Act, Units Ordinance, Directive 71/354/EEC.