EstimatorPad

Door Casing Calculator

Use this door trim calculator to estimate vertical and head casing cut lengths, total linear feet, full stock pieces, waste, and optional local cost from the installed jamb opening.

Enter measurements below. Results update as you type, and optional prices can be added before sharing the estimate.

01 - Door trim

Estimate casing cut lengths and stock pieces

Enter the finished jamb opening, reveal, casing width, corner style, and the stock length sold locally.

Unit system
in
in
in
in
%
ft
USD

Measure the installed jamb before cutting; nominal door size alone is not enough.

Door casing calculation breakdown

Opening and reveal

The reveal expands the casing reference line beyond the inside jamb opening.

Corner style

Long-point cuts include casing width at the 45-degree corners.

One or both sides

One side of the opening are included.

Stock rounding

Total trim plus waste is rounded up to full stock lengths.

The calculation

Door casing = two legs + one head per side

Stock pieces = cut-list packing into full stock lengths, with the waste allowance used as a minimum purchase check

  • Measure the installed jamb opening rather than relying only on nominal door size.
  • Mitered long-point dimensions include the casing face width at the corner.
  • Each required cut must fit inside the selected stock length; the calculator flags stock that is too short.
  • The purchase count respects individual cut fit and the selected overall waste allowance.

Quick examples

36 × 80 in openingCommon interior-door example
1/4-in revealAdds to the casing reference line
2 1/4-in mitered casingControls long-point cuts
8-ft stockEach cut must fit before stock is rounded

Examples are planning checks. Product-label coverage and whole pack sizes control the final purchase quantity.

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Common questions

Understand the result before purchasing

01How much door casing do I need?+

Measure the finished inside jamb width and height, choose one or both sides, add the reveal and casing width required by the corner style, then include a waste allowance and round up to full stock lengths.

02Is this also a door trim calculator?+

Yes. Door casing is the trim installed around the door opening, so this calculator can be used as a door trim calculator for mitered or square-cut casing. It estimates the leg and head cut lengths, total linear feet, and full stock pieces to purchase.

03How do I calculate door trim linear feet?+

For one side, add the two vertical casing lengths and the head casing length, then repeat for the second side when both sides are trimmed. The exact cut lengths depend on the jamb opening, reveal, casing width, and corner style, so the calculator uses those measurements before adding waste and stock rounding.

04What is the reveal on door casing?+

The reveal is the narrow visible strip of jamb left between the inside edge of the casing and the jamb opening. Measure or choose the intended reveal before calculating cut lengths.

05What does long point mean for mitered casing?+

The long point is the outside tip of a 45-degree miter. Mitered vertical and head casing lengths are commonly marked using their long-point dimensions.

06Can I calculate casing for both sides of a door?+

Yes. Select both sides to double the two vertical legs and one head piece required on one side of the opening.

07Does the calculator support craftsman trim?+

Yes. Square-cut or craftsman mode uses square-cut vertical legs and a head piece spanning across the legs. Plinth blocks, rosettes, backband, stool, and apron details require separate adjustments.

08Can I include door casing cost?+

Yes. Enter the local price per stock piece. The calculator applies the price to the rounded number of full pieces to buy.