Horsepower is a unit of measurement of power. This unit was originally created by an engineer from Scotland to compare the power of a steam engine with horsepower. This article will show you how to calculate the engine horsepower of a car, electric motor, and your own body.
Step
Part 1 of 3: Calculating Car Horsepower
Step 1. Find out the torque value of your car
Look in the “technical specifications” section, or look for “torque” in the owner's manual index, and it will show you the torque value. If you don't have an owner's manual, use a search engine to find your car's torque value. For example, search for “torque” and the make, year, and model of your car. Useful search results will appear.
Step 2. Find out the engine speed of your car
These values can also be found in the owner's manual. If your owner's manual doesn't contain this information or you don't have a manual, type the make, year, and model of your car into a search engine followed by the words "engine speed." You will find the value in online resources.
Step 3. Multiply torque by engine speed
Use the formula (RPM * T) / 5.252=HP, where RPM is engine speed, T is torque, and 5.252 is revolutions per second. The first calculation you have to do is multiply the torque by the engine speed.
For example, a Porsche produces 480 torque at 2500RPM. Putting that into the equation (2500 * 480), the result is 1,200,000
Step 4. Divide the result by 5.252
This result is the total horsepower of your car. In the Porsche example, 1,200,000/5,252 = 228, 48. So, the Porsche has 228 horsepower.
Part 2 of 3: Calculating Electric Motor Horsepower
Step 1. Find the current (I), efficiency (Eff), and voltage (V) of the motor
Motor voltage is expressed in volts, current is expressed in amperes, and efficiency is expressed in percentages. These units of measurement should be written on the motor.
Step 2. Determine the horsepower of your electric motor using the formula (V * I * Eff)/746=HP
Multiply the voltage, current, and efficiency and divide the result by 746. For example, the horsepower of a 230v motor, 4 amperes, and 82% efficiency would equal 1 horsepower.
Convert the efficiency to a decimal number before calculating. For example, an efficiency of 82% is equal to 0.82
Part 3 of 3: Calculating Your Own Body's Horsepower
Step 1. Weigh yourself
Find out how much you weigh in pounds. Write down the results. If your scale uses kilograms, multiply the value by 2.2 to find your weight in pounds.
Step 2. Find a ladder that is free from distractions
You will run up these stairs using a stopwatch. So, look for stairs that are not used often.
Step 3. Calculate the total height of the ladder
First, find the height of one step in feet. Then, calculate how many stairs you will climb. Multiply these two numbers, and you'll get the total height of the stairs.
If your ruler uses meters, multiply the height by 3.28 to convert the measurement to feet
Step 4. Calculate the time it takes to run up the stairs
Take the starting position, and when your feet land on the first step, start your trough. When both feet land on the top step, stop the hourglass. Write down your ride duration in seconds. Remember, there are 60 seconds in a minute.
Step 5. Use the formula (m*9.81*h)/t=HP to calculate power
In this example, m = your weight, h = the height of the stairs, 9.81 is the gravitational constant to be taken into account, and t = the time (in seconds) you climbed the stairs. The results obtained are expressed in watts.
For example, if you weigh 180 lbs, and climb a 12-foot ladder in 4 seconds, this equals ((180 * 0.454) * 9.81 * (12 * 0.3048)) / 4 = 733 watts
Step 6. Calculate your body Horsepower
Divide the number of Watts by 746 to find your body's horsepower rating. The result is usually in the range of 1-2 horsepower.
Tips
- Use a calculator for all multiplication and division operations.
- Do the calculation twice to make sure you entered the numbers correctly.