Picture Frame Calculator
Plan frame openings, outer dimensions, and molding length from the art size and framing allowances.
Use it for gallery work, home framing, and quick material estimates before you cut.
Calculated Result
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Run the calculation to see the framing breakdown.
Quick Answer
The picture frame opening is the picture size plus any mat and rabbet allowances, and the outer frame size adds the visible border on top of that.
How to Calculate Picture Frame
- Enter the picture width and height.
- Add the border width you want around the opening.
- Enter a mat width if you are using a mat.
- Read the opening size, outer size, and molding length.
Formula
Opening width = picture width + 2 x (mat width + rabbet allowance)
Outer width = opening width + 2 x border width
Molding length = 2 x (outer width + outer height) x (1 + waste allowance / 100)
Worked Examples
Example 1: An 8 x 10 print with a 1.5 in border and 2 in mat needs an opening about 12.5 x 14.5 in.
Example 2: A 30 x 40 cm artwork with no mat and a 3 cm border needs an outer frame about 36 x 46 cm.
Example 3: A 10 percent waste allowance increases the total molding length by a small margin for cut losses.
How to Interpret Your Results
| Result area | Meaning | Action |
|---|---|---|
| Opening size | Where the art or mat is visible | Confirm it matches the artwork |
| Outer size | Finished visible frame size | Check wall and display fit |
| Molding length | Total stock needed before cuts | Buy extra if corners or waste are likely |
Frequently Asked Questions
Related Calculators
Detail About Picture Frame Calculator
This page focuses on frame geometry and material planning so you can estimate the actual size of the finished frame before ordering or cutting.
References
- OmniCalculator reference page
- Frame openings are typically sized from the visible art area plus the mat overlap.
- Last reviewed: March 2026.