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Door Lining & Architrave Calculator
Calculate door lining sets, architrave lengths, door stops and fixings for any number of UK standard internal doors.
Total doors requiring lining and architrave
Standard UK internal door height is 1981mm
69mm is standard; 57mm minimal; 96mm period
Adds 10% extra for cutting waste and mitres
10% is standard for door linings and architrave
Default: 32mm
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How We Calculate This
This calculator determines the total timber lengths needed for door lining sets, architrave and door stops for any number of doors.
Lining set calculation
Each door needs a lining set of 2 legs and 1 head piece:
- Lining leg length = Door Height + 10mm clearance + 32mm (head piece thickness)
- Lining head length = Door Width + (2 × 32mm lining thickness)
Architrave calculation
Architrave is fitted to a small reveal (margin) set back ~6mm from the inner edge of the lining on all three sides, so the head and legs are sized from that reveal line, not the lining edge. Each side of each door needs 2 architrave legs and 1 head piece:
- Architrave leg length = Door Height + Architrave Width + 10mm (for mitre cut allowance)
- Architrave head length = Door Width + (2 × ~6mm reveal) + (2 × Architrave Width) (the 45° mitre adds one architrave width of run at each corner)
Door stop
Door stop per door= (2 × Door Height) + Door Width
UK standard door sizes
- 610 × 1981mm (2′0″ × 6′6″)
- 686 × 1981mm (2′3″ × 6′6″)
- 762 × 1981mm (2′6″ × 6′6″) — most common
- 838 × 1981mm (2′9″ × 6′6″)
Frequently Asked Questions
The most common UK internal door size is 1981mm high × 762mm wide (6′6″ × 2′6″). Other standard widths are 610mm (2′0″) for small rooms and en-suites, 686mm (2′3″) for bedrooms, and 838mm (2′9″) for wider openings. Standard thickness is 35mm for hollow core and 44mm for solid core doors.
Standard UK door linings use 32×108mm softwood for walls finished with 12.5mm plasterboard on both sides of a 75mm stud (total wall thickness ~100mm). For thicker walls, use 32×133mm or 32×140mm linings. The lining depth should match the finished wall thickness including plaster.
Each side of a door needs 2 architrave legs and 1 head piece. Leg length = door height + architrave width (for the 45° mitre run) + ~10mm cutting margin. Head length = door width + 2× architrave reveal (~6mm each side) + 2× architrave width (the mitre adds one architrave width of run at each top corner). Allow extra for cutting waste.
The most common UK architrave widths are 57mm (budget/minimal), 69mm (standard), and 96mm (period/feature). Ogee and torus profiles in 69mm are the most widely used. For period properties, 96mm or wider architrave with more ornate profiles is appropriate.
Yes, door stops are essential. They prevent the door from swinging through the frame and provide a seal point. Standard door stop is a small moulding (typically 12×38mm or 12×44mm) pinned to the inside of the lining. You need 2 leg pieces and 1 head piece per door.
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Last updated: February 2026
Verified against UK standards · estimates only, confirm with your supplier.