Trim / Molding Calculator

Formula

totalLength = ⌈runLength × (1 + waste/100)⌉  (lf)pieces = ⌈totalLength / pieceLength⌉

Parameters

Piece Length

Standard: 8 ft. Also 10 and 12 ft.

Waste %

Extra for mitered corners and odd-length walls.

Results

Total Length

Linear feet including waste.

Pieces

Trim pieces to purchase.

Example

totalLength = ⌈56 × 1.10⌉ = 62 lfpieces = ⌈62 / 8⌉ = 8 pieces

Common Use Cases

• Baseboard and shoe molding
• Crown molding installation
• Chair rail and wainscoting cap
• Window and door casing

Notes

• Measure wall-to-wall, subtract doorways.
• Mitered corners add waste — increase % for many corners.