Enter power in W, kW, or mechanical horsepower and select the output unit. All directions use one conversion flow. This changes units; it does not calculate motor efficiency or electrical-to-shaft output.

Mechanical horsepower: 550 ft·lbf/s. A unit conversion does not determine motor efficiency or shaft output.

Watts To Horsepower Formula

The following formula converts watts to mechanical horsepower.

HP ≈ W / 745.69987158

Variables:

  • HP is mechanical horsepower (550 ft·lbf/s)
  • W is the power in watts

To calculate mechanical horsepower, divide watts by 550 × 0.3048 × 0.45359237 × 9.80665 (approximately 745.6998715822702).

Watts to Horsepower Conversion Table (Mechanical HP: 1 HP ≈ 745.69987158 W)
Watts (W) Horsepower (HP)
500.067
750.101
1000.134
1500.201
2000.268
2500.335
3000.402
4000.536
5000.671
6000.805
7000.939
7501.006
8001.073
9001.207
1,0001.341
1,5002.012
2,0002.682
2,5003.353
3,0004.023
5,0006.705
Mechanical horsepower: 1 HP ≈ 745.69987158 W. Therefore, 1 W ≈ 0.001341 HP.

What is Watts To Horsepower?

Watts and mechanical horsepower are units of the same power quantity. One mechanical horsepower (550 ft·lbf/s) is approximately 745.6998715822702 W. Converting an electrical input rating to horsepower does not by itself determine mechanical shaft output; that also requires efficiency and operating conditions. Metric and electric horsepower use different definitions.

How to Calculate Watts To Horsepower?

The following steps outline how to calculate the Watts To Horsepower conversion.

  1. First, determine the power in watts (W).
  2. Next, use the formula: HP ≈ W / 745.69987158.
  3. Finally, calculate the horsepower (HP).
  4. After inserting the value of W 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.

Power in watts (W) = 500