In 1 horsepower there are 7.45700e-13 petawatts. Meanwhile in 1 petawatts there are 1,341,022,088,843.8079 horsepower. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Petawatts to Horsepower calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert horsepower (hp) to petawatts (PW), convert hp to watts (W) first, then scale watts to petawatts.
Key facts
Conversion formula (hp to PW)
Quick example
Tip: Petawatts are huge, so the result will almost always be a very small decimal or a number in scientific notation when converting from horsepower.
A petawatt (PW) is a unit of power equal to 1 quadrillion watts. That’s 1,000,000,000,000,000 W (10^15 W). It’s used for very large power levels, such as high-energy lasers and big-scale energy estimates.
Horsepower (hp) is a unit of power often used for engines, motors, and machines. It describes how fast work gets done. Horsepower is common in cars, trucks, lawn equipment, and industrial motors.
To convert horsepower to petawatts, convert horsepower to watts first, then convert watts to petawatts.
Using common definitions:
The exact value depends on the horsepower type you mean.
A petawatt is huge. Horsepower is much smaller by comparison. Since 1 PW = 10^15 W, even large engine ratings turn into tiny numbers in petawatts.
Use the standard that matches your data source:
If the spec sheet only says “hp,” it often means mechanical horsepower.
They relate, but they aren’t the same measurement point.
When converting to petawatts, convert the value you were given. The math is the same, but the input number can differ.
To convert petawatts to horsepower, convert petawatts to watts, then divide by watts per horsepower.
1 petawatt = 10^15 watts.
This sets the scale for the conversion. Since horsepower is under 1,000 watts per hp, the horsepower-to-petawatts result will usually be a very small decimal.
Yes. Sometimes it’s easier because many power ratings are already in watts-based units.
If you have horsepower first, convert hp to watts, then to petawatts.
No. The unit conversion stays the same. Real-world output can change with conditions, fuel, tuning, and load. Those factors change the horsepower number you start with, not the conversion from horsepower to petawatts.
A petawatt is used for extreme power levels, often in short bursts. It may describe peak power in high-energy physics, laser pulses, or very large-scale energy models. It’s not a typical unit for engines, which is why horsepower converts to such small petawatt values.
Example using 1,000 mechanical hp:
This shows how quickly the number shrinks at petawatt scale.
The Calculate Box tool to convert horsepower to petawatts uses the open source script Convert.js to convert units of measurement. To use this tool, simply type a horsepower value in the box and have it instantly converted to petawatts.