Picture Frame Moulding
Calculator
Results
- Inner (rebate) perimeter (cm)
- 180
- Outer perimeter (cm)
- 212
- Moulding length needed (cm)
- 233.2
- Moulding length needed (m)
- 2.332
- Outer frame width (cm)
- 48
Craft results
| Inner (rebate) perimeter (cm) | 180 |
| Outer perimeter (cm) | 212 |
| Moulding length needed (cm) | 233.2 |
| Moulding length needed (m) | 2.332 |
| Outer frame width (cm) | 48 |
formula-map diagram
- Inner (rebate) perimeter (cm)
- 180
- Outer perimeter (cm)
- 212
- Moulding length needed (cm)
- 233.2
- Moulding length needed (m)
- 2.332
- Outer frame width (cm)
- 48
Formula breakdown
Formula
L = 2 × (W + H) + 8 × mw, plus waste= 180
Note
Simplified model: these are standard craft estimates based on rectangular layouts, quoted gauge and nominal densities. Real fabric nap, directional prints, shrinkage, pattern matching, yarn lots and supplier SAP values vary, so always make a swatch or test piece and buy a little extra.
More in Crafts and sewing
See all →Frequently asked questions
Why is moulding length not just the frame's outer perimeter?+
Moulding is cut with 45-degree mitered corners, and the outer edge of each mitered piece is longer than the frame opening's edge by roughly the moulding's face width, so the perimeter calculation must add that extra length at each corner.
How does rabbet depth affect the moulding I need?+
Rabbet depth (how far the moulding's inner lip extends to hold the glass, mat, and backing) doesn't change the length needed, but it does determine whether your artwork and mat stack fit inside the frame without being squeezed or left loose.
Why should I buy extra moulding beyond the calculated length?+
Miter cuts require precision, and a small error means recutting that piece from scratch; buying 10-15% extra, or enough for one additional full side, covers cutting mistakes without a second trip to the shop.
Does the finished opening size or the outer frame size matter more here?+
The finished opening size (matching your artwork or mat) is the starting point, and the calculator adds the moulding's face width and any mat border to determine the outer frame size, which then determines total moulding length needed.
Why do moulding samples list a 'rabbet size' instead of overall width?+
The rabbet size tells you the maximum artwork/glass/backing stack dimension that fits inside that moulding profile, which is the dimension that actually constrains your project, while the moulding's overall visible width is mostly a style and cost factor.