DOORS
Door Size Calculator
Standard door rough opening = door slab width + 2 in and door slab height + 2.5 in, the typical framing allowance for interior doors. Common interior door sizes: 24/28/30/32/36 in wide x 80 in tall; standard exterior doors: 36 in x 80 in.
WINDOWS
Glass Area Calculator
Net glazed area deducts frame width from each side of the window opening: glazed area = window area - frame area, distinct from overall window frame area — used for glass pane ordering and cost.
WINDOWS
Window Area Calculator
Area per window = (width in x height in) / 144; window-to-wall ratio % = total window area / total wall area x 100.