How to use picture frame cutting lengths
What this calculation does
A picture-frame estimate converts the visible opening and moulding face width into four 45-degree long-point lengths.
Measure the visible opening, not the artwork, and use the actual face width of the moulding.
Enter the measurements
- Visible opening width: Measure visible opening width.
- Visible opening height: Measure visible opening height.
- Moulding face width: Measure the face width across the moulding.
Formula and variables
For a 90° rectangular joint with equal 45° mitres: each long-point length = corresponding short-point opening length + 2 × moulding face width. Total = 2 × each pair length.
For each pair, long point equals the corresponding opening dimension plus twice the face width. The total counts two pieces from each pair.
Read the result
A 10×8 in visible opening with 2 in face width needs two 14 in and two 12 in long-point cuts, 52 in total.
Worked example
Inputs: 10 × 8 in visible opening and 2 in face width
- Width pair = 10+2×2 = 14 in; height pair = 8+2×2 = 12 in.
- Total long-point length = 2×14+2×12 = 52 in.
Expected result: two 14 in pieces, two 12 in pieces, 52 in total long-point lengths
Frequently asked questions
Does the opening mean artwork size?
No. The visible opening is the measurement used here; rabbet and artwork fit are separate.
Is 52 in the stock length to buy?
No. It excludes kerf, trim, defects and layout waste.
Conditions, presets and technical notes
Inputs describe the visible opening, not automatically the artwork size or rabbet opening. Rabbet overlap, matting and fitting clearances must be determined separately. Total long-point length does not include kerf, defects, end trim or nesting waste.