Enter the horsepower, torque, and rotational speed into the calculator to determine the missing variable.

HP To RPM Calculator

Enter any 2 values to calculate the missing variable

Hp to Rpm Formula

The following formula is used to calculate the rotational speed (RPM) for a given horsepower and torque. 

RPM = (HP * 5252) / T

Variables:

  • RPM is the rotational speed in revolutions per minute
  • HP is the horsepower
  • T is the torque in pound-feet

To calculate the rotational speed, multiply the horsepower by 5252 and then divide by the torque.

Horsepower to RPM Conversion Table (Assumes Torque = 200 lb-ft)
Horsepower (HP, mechanical) Rotational Speed (RPM)
10263
20525
25657
30788
401,050
501,313
601,576
751,970
1002,626
1253,283
1503,939
1754,596
2005,252
2506,565
3007,878
3509,191
40010,504
45011,817
50013,130
60015,756
* Rounded to nearest RPM. Assumes constant torque τ = 200 lb-ft. Formula: RPM = (HP × 5252) / τ (Mechanical HP).

What is Hp to Rpm?

The relationship between horsepower (HP), torque (T), and rotational speed (RPM) is a fundamental concept in mechanical engineering and automotive industries. Horsepower is a measure of the engine’s power output, torque is a measure of the engine’s rotational force, and RPM is the number of revolutions the engine makes per minute. Understanding this relationship helps in optimizing engine performance and efficiency.

How to Calculate Hp to Rpm?

The following steps outline how to calculate the rotational speed (RPM) from horsepower and torque.

  1. First, determine the horsepower (HP).
  2. Next, determine the torque (T) in pound-feet.
  3. Next, calculate the rotational speed (RPM) using the formula RPM = (HP * 5252) / T.
  4. Finally, calculate the RPM.
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Horsepower (HP) = 300

Torque (T) = 400 lb-ft