How do I lay out coffers?

From the ceiling center out, so they're symmetric.

What are the beams made of?

MDF or wood boxes fixed to blocking or nailers.

Minimum ceiling height for coffers?

About 9 ft so the room doesn't feel cramped.

How deep are coffer beams?

4–8 in depending on ceiling height.

Can coffers have lighting?

Yes — hidden LED strips in the beams or a recessed light per coffer.

Coffered ceiling trim calculator

Ceiling size and coffer grid: you get interior and perimeter beam footage, trim for both sides and the number of pieces.

Purchase quantity

118.11 ft

Net measurement: 118.11 ft · Waste 15 %

Interior beams59.055 ft
Perimeter beam59.055 ft
Trim (two sides per beam + perimeter)203.74 ft
Molding pieces26 pc

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How it's calculated (visible formula)

beams = (coffers along − 1) × width + (coffers across − 1) × length; trim = (2 × beams + perimeter) × (1 + waste)

Net geometric measurement, no waste.
Adjustable waste % for cuts and breakage.
Purchase rounded up to sellable units (boxes, bags, buckets, boards).

See methodology and formula versions

How to calculate it, step by step

Measure ceiling length and width.
Choose the coffer grid (e.g., 3 × 3).
Work out interior and perimeter beam footage.
Multiply by two faces of trim and add the perimeter.
Add 15% waste and round up to pieces.

Worked example: 16 × 13 ft ceiling, 3 × 3 coffers

Beams: 2 × 13 + 2 × 16 = 58 ft
Perimeter: 58 ft
Trim: (116 + 58) × 1.15 ≈ 200 ft

→ About 25 pieces of 8 ft trim.

Common mistakes

Uneven coffers from laying out off a wall.
Too little waste — miters eat material.
Not finding joists to fix beams to.

Pro tips

Lay out from the ceiling center so coffers are symmetric.
Build beams on the floor and lift them assembled when possible.
Fasten beams to joists or blocking, never just drywall.
Fill and sand joints before painting.

From calculation to quote

Add labour, overhead and your margin, and generate the professional PDF.

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FAQs

How much waste for trim?: 15% because of all the miters.
How do I lay out coffers?: From the ceiling center out, so they're symmetric.
What are the beams made of?: MDF or wood boxes fixed to blocking or nailers.
Minimum ceiling height for coffers?: About 9 ft so the room doesn't feel cramped.
How deep are coffer beams?: 4–8 in depending on ceiling height.
Can coffers have lighting?: Yes — hidden LED strips in the beams or a recessed light per coffer.

Sources and standards

Maintained by Srikanta M · Formula v1.0.0 · Verified 2026-09-10 · Updated 2026-09-10 · Limits: quantity estimation, not structural design or site supervision.