Door Casing/Trim Length Calculator

Measure openings accurately and set reveals with builder-grade consistency across projects easily. Choose unit display: decimal, feet‑inch‑fraction, and practical rounding presets for shop prints. Apply brand presets for casing widths and typical reveal defaults fast. Compute totals, export records, and generate cut lists for crews onsite. Optimize sticks across mixed doors, minimizing waste intelligently.

Inputs
All inputs follow the chosen unit.
How many doorways to case.
Casing on one side or both sides of wall.
in
Finished jamb “sight” width of the opening.
in
Finished jamb “sight” height of the opening.
in
Typical 1/8–3/16 in (3–5 mm). Inside short points reference.
in
Face width of the trim stock.
Applies typical casing width and reveal defaults.
Square adds no miter; mitered adds one more miter per side.
%
Allowance for defects, patterning, or mistakes.
ft
Choose preset or enter custom stock length.
in
Per cut removed by blade; applied between pieces.
Rounds purchase to full supplier bundles.
Fraction mode rounds to the chosen denominator.
Use for decimal displays. Fractions use denominator instead.
Batch openings (optional)
# Qty Width Height Faces Action
1
Use batch when doors vary. Otherwise, the single-opening inputs apply.
Summary
Per face cut lengths (outside long points):
  • Side piece length:
  • Head piece length:
Totals (single or batch):
  • Total length per opening (one face):
  • All faces × openings + waste:
  • Required sticks (naïve):
  • Required sticks (optimized):
  • Bundles needed:
  • Sticks (rounded to bundles):
Cut List (per face, single-opening)
# Piece Qty Inside Short Outside Long Miters
No data yet. Enter inputs and click Calculate.
Cutting Plan (optimized across mixed doors)
Stick # Pieces (labels → length) Kerfs Used Waste
No plan yet. Click Calculate to optimize.
Plan includes kerf between pieces. Purchase totals still use your waste allowance separately.
Example Data (typical interior doors)
Door Size (W × H) Reveal Casing Width Faces Notes
28 in × 80 in 3/16 in 2¼ in Both Common bedroom/bathroom interior opening.
30 in × 80 in 1/8 in 2½ in Both Typical hallway or closet opening.
32 in × 80 in 3/16 in 3¼ in One face With wider colonial casing profile.
Example table is for reference only; adjust inputs for your project.
Formulas Used
  1. Inside short lengths
    • Side piece: Hjamb + Reveal (bottom assumed square; add Reveal once at top).
    • Head piece: Wjamb + 2 × Reveal (inside short points).
  2. Miter effect at 45° — Long-point extension equals casing face width per miter end:
    Llong = Linside + nmiters × CasingWidth
  3. Per face length2 × SideLong + HeadLong
  4. TotalsTotal = PerFace × Faces × Openings ; with waste: Totalw = Total × (1 + Waste%/100)
  5. Sticks requiredCeiling(Totalw ÷ StickLength)
  6. Optimization — First‑Fit Decreasing packs piece lengths into sticks, adding kerf between pieces.
Assumes 45° miters. Set side bottoms to mitered if cutting to plinth blocks.
How to Use This Calculator
  1. Select your Units and enter Openings and Faces to case.
  2. Measure Jamb opening width and height along the reveal “sight” line.
  3. Use Brand preset for quick defaults, or set Reveal and Casing width manually.
  4. Choose Display format for Imperial decimals or feet‑inch‑fractions.
  5. Optionally add Batch openings for mixed door sizes and quantities.
  6. Set Saw kerf thickness and Bundle size to match your shop.
  7. Click Calculate for cut lengths, totals, and optimized cutting plan.
  8. Use Download CSV or Download PDF to keep a record.
FAQs

Between consecutive pieces on a stick. The first piece on each stick has no kerf ahead of it; every subsequent piece adds one kerf to the used length calculation.

Each piece is tagged as H, S1, or S2 with door and face indices (e.g., H D2F1). These appear in the plan and exports for quick shop sorting.

It converts the optimized stick count into whole supplier bundles. You choose sticks per bundle; the tool shows bundles required and the rounded stick purchase quantity.

No. The cut plan explicitly adds kerf between pieces. Your waste factor is for defects and handling; keep kerf separate for transparency in planning and procurement.

Yes. Labels are exported to CSV and PDF. If you need a print‑ready sticker sheet with QR codes or barcodes, I can add a label generator page.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.