Door Lining & Architrave Calculator

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″)