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Find the mat opening, outside mat dimensions, and frame fit for your artwork.
Enter your measurements, calculate, and review the assumptions before ordering.
Your project dimensions
Illustrative diagram. Confirm final measurements and fit with your framer before production.
How to measure for a frame and mat
Measure the full sheet that the mat will hold, then decide how much of each edge the mat may cover. The mat opening is the visible window. The mat outside size is the package that fits inside the frame; it is different from the frame’s finished wall footprint.
The starting overlap is 1/8 inch per edge. Change it for your artwork. If a signature, image edge, or decorative border must stay visible, ask us about a different mounting approach.
Example: an 8 Ă— 10 print with 2-inch visible borders
With 1/8-inch overlap on every edge, the window is 7.75 Ă— 9.75 inches. Adding a 2-inch visible border around that window gives an 11.75 Ă— 13.75-inch outside mat. This is a custom package size, not an automatic recommendation to buy a standard 12 Ă— 14 frame.
Already have an 11 Ă— 14 frame? Reverse mode gives centered visible borders of 1.625 inches left/right and 2.125 inches top/bottom for the same opening. Confirm the actual frame fit and depth before ordering.
What to order
Use the outside mat size when discussing frame fit. Suppliers may include their own fitting allowance, so do not add an allowance twice. Finished exterior dimensions depend on the selected moulding profile.
Shop custom matting · Browse custom frames · Read our frame measuring guide
Frequently asked questions
Is frame size the outside measurement?
Usually the listed size describes the artwork or package the frame accepts. The finished exterior depends on the moulding. Check the specific product before ordering.
Why is the mat opening smaller than my artwork?
A small overlap lets the mat cover and retain the sheet edges. The correct overlap depends on the image, paper, mounting method, and details you want visible.
What if my artwork will not fit an existing frame?
Choose a larger frame, a different border, or a different mounting approach. Do not trim valuable or signed artwork based on a calculator result.
Does this calculate cutting instructions?
It prepares planning dimensions. A framer must confirm artwork measurements, fit allowances, depth, mounting, and mat-cutting specifications before production.