1. The ratio of the force produced by a machine: One example of a mechanical advantage is a lever or pulley that can be used to analyze the performance of a machine."
2. The ratio of the output force to the input force for a machine which transmits mechanical energy: "Mechanical advantage is the work produced by a machine, divided by the force applied to it".

"Actual machines can provide a mechanical advantage that is greater than unity (number or numeral one, oneness); however, the greater the mechanical advantage, the greater the distance which the input force must move in relation to the output force."