Select energy, power or duration to find. Enter the other two values, with conversions for mechanical hp, kW, seconds, minutes, hours, J, kJ and MJ.

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Use nonnegative values. hp means mechanical horsepower. Assumes constant delivered power throughout the duration.

hp To Joules Formula

J = HP × 745.6998715822702 × T

Variables:

  • J is the energy (joules)
  • HP is the mechanical horsepower (hp)
  • T is the time (s)

To find energy, multiply mechanical horsepower by 745.6998715822702 W/hp and by duration in seconds. This uses the mechanical horsepower definition, approximately 745.7 W/hp, and assumes constant delivered power. Power alone does not specify energy.

Horsepower to Joules Conversion Table (Energy for 1 s, 1 min, 1 h; 1 mechanical hp ≈ 745.6998715822702 W)
Horsepower (hp) Joules in 1 second (J) Joules in 1 minute (J) Joules in 1 hour (J)
1/6124.2837456.999447419.923
1/4186.42511185.498671129.884
1/3248.56714913.997894839.846
1/2372.85022370.9961342259.769
3/4559.27533556.4942013389.653
1745.70044741.9922684519.538
1.51118.55067112.9884026779.307
21491.40089483.9855369039.075
32237.100134225.9778053558.613
53728.499223709.96113422597.688
7.55592.749335564.94220133896.533
107456.999447419.92326845195.377
1511185.498671129.88440267793.065
2014913.997894839.84653690390.754
2518642.4971118549.80767112988.442
3022370.9961342259.76980535586.131
4029827.9951789679.692107380781.508
5037284.9942237099.615134225976.885
7555927.4903355649.422201338965.327
10074569.9874474199.229268451953.770
*Energy formula: J = mechanical hp × 745.6998715822702 × time in seconds. Constant power; values rounded to 3 decimals.

How to Calculate hp To Joules?

The following steps outline how to calculate the hp To Joules.

  1. First, determine delivered mechanical horsepower (hp). 
  2. Next, determine the duration in seconds, assuming constant power. 
  3. Next, use J = HP × 745.6998715822702 × T.
  4. Finally, select Energy from power and time and calculate the energy.
  5. After inserting the variables 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) = 503

time (s) = 700

FAQs

What is horsepower (hp)?

Horsepower (hp) is a unit of measurement that quantifies the power output of engines and motors. It is commonly used to describe the power produced by a vehicle’s engine, machinery, or electric motors.

How is horsepower converted to joules?

Multiply mechanical horsepower by 745.6998715822702 to obtain watts (J/s), then multiply by the duration in seconds. The formula is J = HP × 745.6998715822702 × T. It assumes constant delivered power; use average power if the output varies.

Why is it important to convert horsepower to joules?

This calculation gives delivered energy over a specified duration. Comparing efficiency requires both input and output energy; delivered horsepower and time alone do not determine efficiency or input energy consumption.

Can this formula be used for any type of engine or motor?

Yes, when the entered power is the delivered output and uses the correct definition. This calculator uses mechanical horsepower (1 hp ≈ 745.6998715822702 W), not metric horsepower. With constant power and duration, J = HP × 745.6998715822702 × T; use average delivered power if it varies.