How do you convert LRA to HP?

LRA (lock rotor amps) can be converted to HP using this formula: (LRA Watts x Volts)/ 746 Watts = Horsepower. You can also use the BTUh. For example, 18,000 BTUh equals 2 HP or 24,000 2.5 HP. If you have a RLA rating on your compressor instead, please note that the LRA can be 5 less than a LRA/FLA and some can be 7 times less).