Electrical Motor Power, Velocity and Torque Equations. Torque in Imperial units can be calculated as. T inlb = P hp 63025 / n (1). where . T inlb = torque (in lb f). P hp = horsepower delivered by the electric motor (hp). n = revolution per minute (rpm) Alternatively . T ftlb = P hp 5252 / n (1b). where. T ftlb = torque (lb f ft). 1 ft lb f = 1.356 Nm
