How to Calculate Horsepower
Get your car’s torque numbers., Find your car’s engine speed., Multiply the torque by the engine speed., Divide the product by 5,252., Figure out the current (I), efficiency (Eff), and voltage (V) of the motor.The voltage of the motor will be...
Step-by-Step Guide
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Step 1: Get your car’s torque numbers.
Look under the “technical specs” section, or look for “torque” in the index of the owner’s manual, and it will give you the torque value.
If you do not have the owner’s manual, try using a search engine to find your car’s torque.
For instance, search “torque” and your car’s make, year, and model, and a helpful result should come up. -
Step 2: Find your car’s engine speed.
This can also be found in your owner’s manual.
If your owner’s manual does not have this information or if you do not have the manual, type your car’s make, year, and model in a search engine followed by the words “engine speed.” An online resource should have this number. , You will be using the formula (RPM * T) / 5252=HP, where RPM is the engine speed, T is the torque, and 5,252 is radians per second.
The first calculation you want to do is multiply the torque and the engine speed.
For example, a Porsche generates 480 of torque at 2,500RPM.
Expressed in terms of the equation, that is (2500 * 480), which equals 1,200,000. , The result is your car’s horsepower.
In the Porsche example, 1,200,000/5252 =
228.48, so the Porsche has 228 horsepower. , The motor should have these units of measurement written on it. , Multiply the voltage, the current, and the efficiency, then divide the result by
746.
For example, the horsepower of a 230v motor pulling 4 amps and having 82% efficiency would equal 1 horsepower.
Convert the efficiency into a decimal before calculating.
For example, a 82% efficiency would equal .82. , Find out how much you weigh in pounds.
Write your weight down.
If your scale uses kilograms, multiply this number by
2.2 to find your weight in pounds. , You’ll be running up these stairs with a stopwatch, so try to find a stairway that is not frequently used. , Multiply these two numbers, and you will have the total height of the stairs.
Write down the height.
If your ruler uses meters, multiply the height by
3.28 to convert the measurement into feet., Get a running start, and when your foot lands on the first step, start your stopwatch.
When both feet are on the top step, stop your stopwatch.
Write down the duration of your climb to the top in seconds.
Remember, there are 60 seconds in every minute. , In this instance, m = your weight, h = the height of staircase,
9.81 is the gravitational constant that must be taken into account, and t = time (in seconds) of your climb.
The resulting number you get is expressed in watts.
For example, if you weigh 180 lbs, and climb a 12-foot staircase in 4 seconds, that equals ((180 * .454) *
9.81 * (12 * .3048)) / 4 = 733 watts. , Divide the number of Watts by 746 to find out your horsepower rating.
This result is usually between 1-2 horsepower. -
Step 3: Multiply the torque by the engine speed.
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Step 4: Divide the product by 5
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Step 5: Figure out the current (I)
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Step 6: efficiency (Eff)
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Step 7: and voltage (V) of the motor.The voltage of the motor will be expressed in volts
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Step 8: the current will be expressed in amps
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Step 9: and the efficiency will be expressed as a percentage.
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Step 10: Using the formula (V * I * Eff)/746=HP
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Step 11: determine your electric motor’s horsepower.
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Step 12: Weigh yourself.
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Step 13: Find a stairway that is free from obstructions.
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Step 14: Measure the total height of the stairs.First
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Step 15: find the height of one stair in feet.Then
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Step 16: count how many stairs are in the stairwell you will be running up.
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Step 17: Time how long it takes you to run up the stairs.
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Step 18: Use the formula (m*9.81*h)/t=HP to calculate your watts.
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Step 19: Calculate your Horsepower.
Detailed Guide
Look under the “technical specs” section, or look for “torque” in the index of the owner’s manual, and it will give you the torque value.
If you do not have the owner’s manual, try using a search engine to find your car’s torque.
For instance, search “torque” and your car’s make, year, and model, and a helpful result should come up.
This can also be found in your owner’s manual.
If your owner’s manual does not have this information or if you do not have the manual, type your car’s make, year, and model in a search engine followed by the words “engine speed.” An online resource should have this number. , You will be using the formula (RPM * T) / 5252=HP, where RPM is the engine speed, T is the torque, and 5,252 is radians per second.
The first calculation you want to do is multiply the torque and the engine speed.
For example, a Porsche generates 480 of torque at 2,500RPM.
Expressed in terms of the equation, that is (2500 * 480), which equals 1,200,000. , The result is your car’s horsepower.
In the Porsche example, 1,200,000/5252 =
228.48, so the Porsche has 228 horsepower. , The motor should have these units of measurement written on it. , Multiply the voltage, the current, and the efficiency, then divide the result by
746.
For example, the horsepower of a 230v motor pulling 4 amps and having 82% efficiency would equal 1 horsepower.
Convert the efficiency into a decimal before calculating.
For example, a 82% efficiency would equal .82. , Find out how much you weigh in pounds.
Write your weight down.
If your scale uses kilograms, multiply this number by
2.2 to find your weight in pounds. , You’ll be running up these stairs with a stopwatch, so try to find a stairway that is not frequently used. , Multiply these two numbers, and you will have the total height of the stairs.
Write down the height.
If your ruler uses meters, multiply the height by
3.28 to convert the measurement into feet., Get a running start, and when your foot lands on the first step, start your stopwatch.
When both feet are on the top step, stop your stopwatch.
Write down the duration of your climb to the top in seconds.
Remember, there are 60 seconds in every minute. , In this instance, m = your weight, h = the height of staircase,
9.81 is the gravitational constant that must be taken into account, and t = time (in seconds) of your climb.
The resulting number you get is expressed in watts.
For example, if you weigh 180 lbs, and climb a 12-foot staircase in 4 seconds, that equals ((180 * .454) *
9.81 * (12 * .3048)) / 4 = 733 watts. , Divide the number of Watts by 746 to find out your horsepower rating.
This result is usually between 1-2 horsepower.
About the Author
Jacqueline Lane
Specializes in breaking down complex DIY projects topics into simple steps.
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