In 1 horsepower there are 7.45700e-10 terawatts. Meanwhile in 1 terawatts there are 1,341,022,088.843808 horsepower. Keep reading to learn more about each unit of measure and how they are calculated. Or just use the Terawatts to Horsepower calculator above to convert any number.
* Values rounded to 6 decimal places for readability
To convert horsepower (hp) to terawatts (TW), convert horsepower to watts (W) first, then scale watts to terawatts.
TW = hp × 746 ÷ 10¹²
Use this same method for any horsepower to terawatts conversion.
Horsepower to terawatts is a power unit conversion. It changes horsepower (hp) into terawatts (TW) so you can compare small power ratings with very large ones. This is common when scaling up from engines and motors to grid-level power.
For mechanical horsepower, 1 hp = 0.000000000745699872 TW (about 7.45699872 × 10^-10 TW).
That’s a tiny fraction of a terawatt because a terawatt is a trillion watts.
For mechanical horsepower, 1 TW = 1,341,022,089.6 hp (about 1.341 billion hp).
This helps show how large a terawatt is compared with everyday machines.
Use this formula (mechanical horsepower):
You can also convert through watts:
If you have 1,000,000 hp (one million hp):
Most conversions use mechanical horsepower:
Other types exist, and they change the result:
Horsepower is built for engines and motors. Terawatts are used for huge systems like national power use. Since 1 TW = 1,000,000,000,000 W, it takes over a billion horsepower to reach one terawatt.
Convert in two steps (mechanical hp):
This method is easy to check and helps avoid unit mix-ups.
Horsepower and terawatts measure power, which is the rate of doing work.
Kilowatt-hours (kWh) measure energy, which is power used over time.
A simple link:
A typical car might be 150 to 300 hp. In terawatts, that’s about:
These values are very small because terawatts are meant for massive totals.
For most uses, 3 to 6 significant digits is enough. Terawatt results often show up in scientific notation, so rounding too early can hide meaningful differences when you work with large horsepower totals.
Scientific notation keeps the number readable. For mechanical horsepower:
For larger values, scale the horsepower and keep the exponent format. This cuts down on zeros and reduces reading errors.
The Calculate Box tool to convert horsepower to terawatts 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 terawatts.