Build TheoryCasing Cut Planner · All tools

Door frame — what to cut

Type like a tape: 30 3/4. Get the panels to cut.

Assembled frame
TOPLEFTRIGHT
Top panel37 1/4"
⟋ left cutright cut ⟍37 1/4"
Side panel× 281 1/2"
⟍ top cutfloor · straight

Every slanted cut is 45°. To mark it: measure the length on the outer edge, step in 3" on the inner edge, join the two marks. Keep pieces face-up so the design lines up at the corner.

Want it installed right?

Build Theory handles trim, doors, custom millwork, and full renovations across the GTA.

Request a quote →