The watt (W) is the SI base unit of power, defined as one joule per second, measuring the rate of energy transfer. From light bulb brightness ratings to phone charger output, the watt appears in everyday product specifications worldwide. One watt equals exactly 1 joule per second, or about 0.001341 horsepower.

Foot-pounds per second (ft·lbf/s) equals approximately 1.356 watts, an imperial power unit occasionally used in mechanical engineering contexts. While less common than horsepower for engine ratings, it provides a direct connection between torque and rotational speed. One foot-pound per second equals about 1.356 watts or 0.00182 horsepower.