A building surface area measurement system for efficiently measuring the surface area for a room. The building surface area measurement system generally includes a housing having a triangular shaped base, wherein the housing includes a first side positionable adjacent to a first wall and a second side positionable adjacent to a second wall in a corner, a first measuring unit within the housing directed parallel to the first wall to measure the width of the first wall, a second measuring unit within the housing directed parallel to the second wall to measure the width of the second wall, and an upper measuring unit directed upwardly parallel to the height of the walls. A control unit within the housing is in communication with the measuring units and utilizes the measurement data to calculate the total surface area of the room or the two walls. A display unit within the housing displays the calculated information.