Horsepower

Horsepower, abbreviated as HP, is a measure of power or the rate of doing work. It is typically used to describe the work of an engine or machine and is the equivalent of moving 33,000 pounds through the distance of one foot in one minute.

 

Horsepower formulas

\(\large{ HP = \frac{ \tau \; s }{ 5252 }   }\)
\(\large{ HP = W \;  \left(  \frac{ v }{ 234 } \right)^3  }\)	(estimated HP after quarter mile trap speed method)
\(\large{ HP =  \frac{W}{ \left(  \frac{ ET }{ 5.825 } \right)^3 }   }\)	(estimated HP after quarter mile ET (elapsed time) method)

Where:

\(\large{ HP }\) = horsepower

\(\large{ s }\) = speed (rpm)

\(\large{ \tau }\)  (Greek symbol tau) = torque

\(\large{ v }\) = velocity

\(\large{ W }\) = weight

Solve for:

\(\large{ s = \frac{ 5252\; HP }{ \tau } }\)

\(\large{ \tau = \frac{ 5252\; HP }{ s }   }\)

 

horsepower conversion table

Horsepower Conversion Table
Multiply	By	To get
	2545.45766	BTU per hour, BTU/hr
	42.42429433	BTU per minute, BTU/min
	0.707071572	BTU per second, BTU/sec
	1980796.979	foot pound-force per hour
	33013.28298	foot pound-force per minute
	550.221383	foot pound-force per second
	1	horsepower, hp
	17702.8489	pound square foot per cubic second
	0.212121472	ton of refrigeration, ton
	2.6856E+13	dyne centimeter per hour
	4.476E+11	dyne centimeter per minute
	7460000000	dyne centimeter per second
	2685600	joule per hour
	44760	joule per minute
	746	joule per second
	746	watt, W
	0.746	kilowatt, kW
	0.000746	megawatt, MW
	0.000000746	gigawatt, GW
	2685600	newton meter per hour
	44760	newton meter per minute
	746	newton meter per second