Before revision: For imperial units, where Php is the power in horsepower τlb·ft is the torque in pound-feet ωRPM is the rotational velocity in revolutions per minute For metric units, where PW is the power in Watts (W) τN·m is the torque in Newton metres (Nm) ω is the rotational velocity in radians/second (rad/s) ω = ωRPM .
After revision: or U.S. customaryFor imperial units, where Php is the power in horsepower τlb·ft is the torque in pound-feet ωRPM is the rotational velocity in revolutions per minute For metric units, where PW is the power in Watts (W) τN·m is the torque in Newton metres (Nm) ω is the rotational velocity in radians/second (rad/s) ω = ωRPM .