The pound-foot (lb·ft) is a unit of torque and rotational energy that measures the rotational force applied around a pivot point. Specifically, it quantifies the torque resulting from a one-pound force applied at a perpendicular distance of one foot from the pivot point. The symbol for pound-foot is lb·ft, and it is commonly used in the United States and a few other countries that have not adopted the metric system. In engineering, automotive, and aviation applications, the pound-foot is a standard unit for expressing torque, particularly in the specification of engine output and fastener tightness. Understanding and accurately applying measurements in pound-feet are crucial in both practical and scientific contexts to ensure the reliability and efficiency of mechanical systems and structures.