Rectangle Area (Square Footage)
Compute the area and perimeter of a rectangular room, yard, or surface. Use for square footage from length × width.
Limitations: Perfect rectangle only. Irregular rooms (L-shapes, bays, alcoves) must be split into rectangles and summed. Does NOT add waste margin for flooring or paint — add 5–10% yourself when purchasing materials.
What to do next: Quick square-footage: enter 15 × 18 and the result is 270 ft². For an L-shaped room, break it into two rectangles and add their areas.