Work is defined as a force acting upon an object to displace the object. In metric units, the standard unit for length or displacement is the meter, and the standard unit for a force is the newton. Therefore, the standard unit for work is the Newton meter, or joule.
There are several English units for work. The pound-force-foot is equivalent to 1.34 joules. Similar units for work include the pound-force-inch and the ounce-force-inch. A pound-force is 1 pound multiplied by the force of gravity. The horsepower-hour, yet another unit of work, is derived from the common horsepower unit of force. It takes 2,680,965 horsepower-hours to equal 1 joule.