width() - returns the width of an element.
innerWidth() - returns the width of an element (includes padding).
outerWidth() - returns the width of an element (includes padding and border).
outerWidth(true) - returns the width of an element (includes padding, border and margin).
height() - returns the height of an element.
innerHeight() - returns the height of an element (includes padding).
outerHeight() - returns the height of an element (includes padding and border).
outerHeight(true) - returns the height of an element (includes padding, border and margin).