Door & Window Casing Calculator

What this calculation does not cover

• The stick figure is a length division — the run with waste divided by the stock length and rounded up — and it takes no account of which piece has to come out of which stick. A 2.032 m door leg cut from an 8 ft (2.44 m) stick leaves 406 mm, too short for the 864 mm head, so four identical doors take ten sticks on the bench against the nine that division returns. Openings of different sizes have to be run separately and their stick counts added, because offcuts from one run are not pooled into another.
• No casing width is collected, so the run is the bare opening and nothing else. A mitred picture frame round a window adds about eight times the casing width, since each of the four pieces runs past the opening at both ends: 456 mm for a 57 mm profile and 712 mm for an 89 mm one. A door adds about four times the casing width, roughly 0.75 linear ft on a standard opening with a 2 1/4 in architrave, which is already half of the default 10% allowance before a single mitre offcut is cut.
• Rough opening, finished jamb and door leaf are three different heights and the calculator simply uses whichever you type. The 2.032 m default is an 80 in leaf rather than a rough opening, and it is not the leg length either: a leg is cut from the finished floor to the top of the head casing, which with an 89 mm architrave over that leaf sits past 2.13 m and will not come out of a 2.1 m stick at all, even though the total-length arithmetic accepts that stock length without complaint.
• The window option assumes a four-sided picture frame. A window finished with a stool and apron is cased on three sides instead, so the four-sided figure overstates it by one opening width per window — 0.9 m on a 1.2 m by 0.9 m opening — while the stool itself, which runs past the legs by a horn at each end, and the apron beneath it are different sections this page does not produce.
• Plinth blocks and corner rosettes change the geometry the figure assumes: a plinth block takes its own height, commonly 130 to 150 mm, off the foot of each leg, and rosettes remove the mitres so the head is cut square between them rather than long-point to long-point. Extension jambs or a jamb rip, needed wherever the wall finish stands proud of the jamb face, are a separate material in a separate width and are outside this total. The height and width fields stop at 3 m, so a 12 ft (3.66 m) patio slider or a wide bifold opening has to be split across runs.