Power Unit Converter: kW, HP, Watt Online & Free
Do you want to know the actual horsepower of your car when only kW is listed in the technical specifications? Do you need to convert BTU air conditioning power to understandable Watts? Or are you just looking for energy-saving light bulbs? Our online power calculator will do the math for you – instantly and accurately.
We cover everything from the microworld of electronics (Watts) to the automotive industry (horsepower - both hp and metric) and energy production (Megawatts, Gigawatts). Everything works online, for free, and without installation.
Why is this converter better than mental arithmetic?
Converting power isn’t just about shifting decimal points. Did you know, for example, that there are two different standards for “horsepower”? Our tool automatically handles these technical nuances.
- “Auto-Moto” and “Electro” Mode: Whether you’re dealing with an internal combustion engine (HP) or an electric vehicle (kW), the calculator handles it.
- Distinction between Imperial and Metric Units: We are among the few who distinguish between British horsepower (
hp- mechanical) and the European one (hp(M)- metric), which you’ll find in Czech technical registrations. - Scientific Accuracy: Do you need to convert the enormous power of a power plant (GW) to watts? Our “Quick Overview” displays the result in a precise scientific format, so you won’t get lost in zeros.
Units Glossary: Do you understand power?
Power is a physical quantity that tells us “how quickly work is done.” However, each field uses a different language. Here’s your cheat sheet:
| Unit | Abbreviation | Where it’s used | Typical value |
|---|---|---|---|
| Watt | W | Electronics, light bulbs, chargers. | LED bulb (10 W), mobile charger (20 W). |
| Kilowatt | kW | Cars (in registration), electric motors, appliances. | Vacuum cleaner (1.5 kW), Skoda Octavia (110 kW). |
| Horsepower | hp / hp(M) | Car marketing, motorcycles, tractors. | Regular car (100–150 horsepower), Formula 1 (1000+). |
| Megawatt | MW | Power plants, large ships, locomotives. | Wind turbine (2–5 MW). |
| Gigawatt | GW | National energy. | Temelín Nuclear Power Plant block (approx. 1 GW). |
| BTU/h | BTU/h | Air conditioning, heat pumps. | Portable air conditioner (9000 – 12000 BTU/h). |
The Biggest Pitfall: Not all horsepower is the same
If you’re a motorsport enthusiast or buying a car from abroad, pay attention. Our converter in the “Quick Overview” section shows two different values. Why?
- hp (Mechanical Horsepower): Mainly used in the USA and Great Britain. The value is approx. 745.7 W.
- hp(M) (Metric Horsepower): Used in Europe (also designated as k, PS, or cv). The value is approx. 735.5 W.
Practical example: You have a car with a power of 100 kW.
- In the USA, they would say it has 134 hp (mechanical horsepower).
- In Germany or the Czech Republic, we would say it has 136 horsepower (PS). The difference is small, but for high-performance sports cars, it can amount to tens of horsepower. Our tool will show you both values, so you are always informed.
Instructions: How to find power in seconds
Whether you’re in an electronics store or reading a car review, the process is easy:
- Enter a number: E.g., the value
110(kW from the technical registration). - Select units: On the left, choose “kilowatt”; on the right, for instance, “metric horsepower”.
- Result: You immediately see that 110 kW is exactly 149.5 horsepower.
- Bonus: Look at the table below. You’ll also find out, for example, what cooling power an air conditioner would need in BTU/h to dissipate this power (approx. 375,000 BTU/h).
Frequently Asked Questions (FAQ)
What's the difference between kW and kWh?
This is the most common misconception.- kW (Kilowatt) is power (engine strength, appliance input). It's like the "speed" at which water flows.
- kWh (Kilowatt-hour) is energy (consumption). It's the amount of water that has flowed into a bucket over an hour.
How many kW is one horsepower?
For a quick mental conversion: 1 kW = approx. 1.36 horsepower. 1 horsepower = approx. 0.74 kW. So, if you have a 100-horsepower car, it has roughly 74 kW. For an exact number, use our widget, which calculates to decimal places.What does 12000 BTU mean for air conditioning?
BTU per hour is an older unit of power. 12,000 BTU/h corresponds to approximately 3.5 kW of cooling capacity. This is the standard capacity for an air conditioner in a typical room (approx. 25-30 m²).What does ft-lb/s mean in the table?
The unit "foot-pound per second" is an imperial unit of power. It essentially defines mechanical horsepower (1 hp = 550 ft-lb/s). It is rarely encountered in our regions; it is mainly used by engineers in the USA for calculating torque and engine power.What does "e-4" or "e-7" mean in the result?
When converting a small unit (Watt) to a huge one (Megawatt or Gigawatt), a number with many zeros appears (e.g., 0.0001). To fit the number on a line and make it clear, scientific notation is used.1.00e-4 means you move the decimal point 4 places to the left.