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Engine Horsepower calculator

Horsepower Calculator

Calculation Method:

Vehicle weight ?


Time ?


Speed on Finish ?








To Calculate:

Engine RPM:

Engine Torque:


Engine Horsepower:

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An online horsepower calculator will use different horsepower calculation methods to estimate how much power your vehicle is producing. This calculator for horsepower works on the principles of horsepower formula and to convert between different units. Keep reading to exactly know about how to calculate horsepower of engines step by step and with a calculator, horsepower equation, and certain terms related-to horsepower!

So, first, explore the most basic definition of horsepower!

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What Is Horsepower?

Horsepower can be defined as a unit that is used for the measurement of power. In simple words, it can be explained as a rate at which a certain amount of work is being done. It normally elaborated in reference to the output of working engines in different vehicles. Two common types that are being frequently used in the universe are mechanical horsepower which is also known as imperial horsepower and is equal to 745.7 watts. Another one is metric horsepower, which is equivalent to 735.5 watts.

The basic concept and measurement of horsepower can be varied in different geographical areas. Its SI unit is watt in most of the countries around the globe.

Also, you can use this free physics torque calculator to determine the torque of a rotating object, torque on a flat coil, and vector torque.

What is The Genesis of Horsepower?

To understand the basic concept of horsepower we have to look at its origin in the 18th century. The creation of a steam power system was about delivering the required amount of power. At this moment in time an engineer James Watt (1736-1819), was trying to work for the betterment of the steam engine concept. Watt took notice in the working phenomenon of horses that dragged, pushed, and lifted heavyweight in workshops, mills, and pits. He was considering a method to demonstrate that his industrial steam engine possibly will out workhorses and he laid the foundations of horsepower after that.

How to Calculate Horsepower (Step-By-Step)?

Horsepower can be calculated by different precise methods that are listed below. It can be calculated manually with the help of formulas as well as with the support of a horsepower calculator.

Elapsed Time (ET) Technique:

In this method, we require the total weight of our vehicle and the elapsed time (ET) that was taken to cover a quarter-mile which is equivalent to 402.3 meters. For this method the horsepower equation is:

  • HP = Weight x (the speed at which vehicle is moving (divided by) 234)3
  • If the weight is 50 and speed is 7 then by putting values in the above equation the HP will be 47.4 kilowatts.

Trap-Speed technique:

In this method, we require the weight of the vehicle and the speed at which the vehicle finished a quarter-mile that is equivalent to 402.3 meters. The formula for horsepower for this type will be:

  • Horsepower = Weight× (Speed )3 divided by 234.
  • If the vehicle weight is 20 and speed is 30 mph, then putting values in the equation the horsepower will be 0.2 kilowatts.

Definition method:

This method requires all those values that are required to elaborate the horsepower in the international system of units. Such a method involves the use of dynamometers. It involves the workout of the engine and the actual rate of RPM. The horsepower formula for the definition method is:

  • Horsepower = force (distance divided by time)
  • If the F is 10N distance is 5m and speed is 23sec then on putting values in the above formula the horsepower will be 2.17 watts.

RPM & Torque technique:

By this technique, we calculate horsepower by using the RPM and actual torque of the engine.

  • The formula for this approach is: horsepower = RPM (multiplied by) torque (divide by) 5,252
  • If the RPM of any vehicle motor is 5,600 RPM and torque is 350 foot-pounds, then by putting values in the formula we can calculate horsepower of the engine.
  • (5,600 × 350) ÷ 5,252 = 373.19 HP

Horsepower calculator is the most convenient option to measure the actual HP of an engine without any error.

Furthermore, it adjusts the units according to requirements and delivers output in different types of horsepower as well.

What are Different Types of Horsepower?

There are different types of horsepower listed below:

Mechanical horsepower:

It is defined as the pound force or kilogram force exerted by the engine of the vehicle. One mechanical horsepower is equal to 550 ft⋅lbf/s or 746 W.

Metric horsepower:

It is normally indicated by various units such as PS, cv, hk, pk, ks, and ch. DIN 66036 describes one metric horsepower because the power to increase a mass of 75 kilograms contrary to the force of gravity over a precise distance of one meter that is covered in one second is equivalent to 98.6% of metric horsepower.

Tax horsepower:

Tax horsepower represents a non-linear rating for any motor vehicle for tax purposes. The monetary power is (P / 40)1.6 + U / 45. P represents the amount of maximum power in kilowatts and U represents the amount of emitted carbon dioxide in one kilometer.

Electrical horsepower:

Nameplates that are attached to electrical motors demonstrate their power output. They do not demonstrate their power input. Electrical horsepower represents power output in watts or kilowatts.

Hydraulic horsepower:

It represents the power that is present in any hydraulic equipment. It can be computed by the formula:

  • Hydraulic horsepower = P x rate of flow / 1714

Boiler horsepower:

Boiler horsepower defines the capacity to deliver the steam of any is a boiler to a steam engine. One boiler horsepower is equivalent to the thermal energy that is required to vaporize 34.5 lb of water at a temperature of 212 °F in sixty minutes. The term “boiler horsepower” was established at the Philadelphia Centennial Exhibition in 1876. These days “boiler horsepower” is defined as a boiler thermal output which is equal to 33,475 Btu/h. In some countries such as Australia, it is still used to measure boiler output.

Drawbar horsepower:

This category represents the power of a railway engine or an agricultural tractor that is being used to pull things. This category is basically a measured figure. To determine the maximum amount of available power, a manageable weight is obligatory. It usually measured by:

  • P(hp) = F(IBf) x V(mph) / 375

RAC horsepower:

This category was introduced by the Royal Automobile Club in Britain. It was used to denote the power of 20th-century British cars. It is an estimated category that is based on the bore size, a total number of cylinders, and efficiency of a car engine. It is measured by RAC h.p. = 2/5 D2n. Whereas D is representing cylinder diameter and n represents the total number of present cylinders in the car.

Measuring Horsepower:

Horsepower is usually measured by a dynamometer. It requires a definite volume of power to cause the rotor to go around at a precise speed. If the engine of your car is running at 5000 rotations in one minute, (rpm), then you can observe the amount of load that turns on the dynamometer for calculating its horsepower. However, every engine has the highest amount of horsepower that is known as its RPM value.

Horsepower Vs. Torque:

Torque is just a force that is acting upon any object from a certain distance to put it into a motion whereas horsepower is a torque but multiplied by RPM, or we can say that it is the measurement of a procedure that how speedily any engine can complete a definite quantity of work in a required time.

  • The formula for measuring torque is: t = r (multiplied by) F
  • The formula for measuring horsepower is: hp = torque (multiplied by) PRM / 5252

Gross or Net Horsepower:

Net horsepower is measured where the crankshaft of any engine is located. It does not take any sort of transmission losses. It produces rankings in closer alignment with the power that is being created by the engine because it is in reality organized and sold. However Gross horsepower is the actual measurement of output created by the engines at the flywheel. It will be measured only when the engine is not fitted in the vehicle.

About Horsepower Calculator:

This horsepower calculator figures out the horsepower of your vehicle by using the definition of horsepower, time elapsed, trap speed, and RPM & torque method. In simple words, the calculator tells you how much horsepower your vehicle is producing approximately by using different Hp methods.

How is horsepower measured by using Horsepower Calculator:

You can easily and accurately calculate the horsepower with this calculator, just follow the given steps for the speedy and exact calculations.

Swipe on!

For Elapsed time method:


  • First of all, enter the weight of the vehicle in kgs or in lbs.
  • Then, put the elapsed time in sec/min/hrs that is taken by vehicle to cover the quarter mile.
  • Hit the calculate button.


  • Engine power in mechanical horsepower.
  • Engine power in metric horsepower.
  • Engine power in kilowatts.
  • Engine power in foot-pounds per second.

For Trap-speed method:


  • First of all, enter the weight of the vehicle in kgs or in lbs.
  • Then, plug in the speed of the vehicle (mph, km/s, km/h, m/s) at which it is finished the quarter mile.
  • Hit the calculate button.


  • Engine power in mechanical horsepower.
  • Engine power in metric horsepower.
  • Engine power in kilowatts.
  • Engine power in foot-pounds per second.

For RPM & torque method:


  • First of all, you have to select the calculate option from the dropdown. (If you want to calculate the horsepower of the engine, then select the ‘engine horsepower ‘option and if you want to calculate the torque of the engine, then select ‘engine torque’ option.)
  • Then, plug in the revolution per minute (RPM) of the engine.
  • After this, enter the torque of the engine.
  • Hit the calculate button.

Outputs:(For Engine horsepower)

  • Engine power in mechanical horsepower.
  • Engine power in metric horsepower.
  • Engine power in kilowatts.
  • Engine power in foot-pounds per second.

Outputs:(For Engine Torque )

  • Torque of the engine

For Definition method:


  • First of all, you have to enter the force.
  • Then, plug in the distance in m/km/yd covered by the vehicle.
  • After this, enter the time in which the vehicle covers the distance.
  • Hit the calculate button.


  • Engine power in watts.
  • Engine power in mechanical horsepower.
  • Engine power in metric horsepower.
  • Engine power in kilowatts.
  • Engine power in foot-pounds per second.
  • Engine power in electrical horsepower.
  • Engine power in boiler horsepower.

Frequently Ask Questions(FAQ’s):

How is electric motor horsepower calculated?

To calculate the horsepower of an electric motor, the following formula is used,

HP = (V * I * Eff) / 746


V is the voltage,I is the current and Eff is the efficiency of the electric motor.

Why is it called a horsepower?

In the early 1800s, when the steam engine began to do work of horses in mines, then owners of mines asked how many horses would replace an engine. That’s why the steam engine was named horsepower.

How fast is 345 horsepower?

The engine with an HP of 345 accelerates at 60mph in 4.8 seconds.

How fast is 180 horsepower?

An engine with 180HP accelerates from 0-100 km/h in just 7-10 seconds depending on weight and gearbox.IN 70’s and 80’s a car with 180HP has sports car performance.

How many kWh is 1 HP?

As the kilowatt-hour is the measure of energy while Horsepower is the measure of power so you can convert kilowatt-hour to only horsepower-hour.As

1kWh = 1.3404825737 hph.

How many ftlbs is 1 HP?

1 horsepower is approximately equal to the 550 ft lbs.

Do electric motors have horsepower?

Like the gasoline engine, an electric car’s motor also generates power that motions the wheels to put things in motion. Power of electric motors measured in either horsepower or in kilowatts.

How many amps are in a horsepower?

1 horsepower is approximately equal to 6.91 amperes.



This horsepower calculator will answer the question of what is my car’s horsepower. It calculates the HP of your vehicle with 4 different kinds of methods. Whenever you want to make a quick estimate about peak horsepower in your daily life or in professional grounds then take its support for the speedy answers.


From the source of Wikipedia: Horsepower, History, Calculating power, Definitions, and much more!

From the source of crowntoyota: What is the Horsepower of the 2020 Toyota Tundra?

From the source of toppr: The formula for Horsepower calculation and Solved Examples on Horsepower Formula