The approximate rough opening dimensions for a standard front door is 82 1/2 inches by 38 inches. This opening in an exterior wall's framework accommodates a 80-inch-by-36-inch front door.
To determine the right rough opening dimensions for any door, a construction worker adds 2 inches to the width of the exterior door and 2 1/2 inches to the door's height. An opening this size allows for either a pre-hung or standard door, as well as shims, a door jamb and the necessary finishing framework. A door framing plan also specifies that the rough opening uses double studs to reinforce that area.