Enter your artwork dimensions, mat width, and frame border width to calculate the perfect picture frame size. You'll get the outer frame dimensions, mat opening size, and frame perimeter — everything you need to order or build a custom frame.
Outer Frame Width
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Outer Frame Height
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Mat Opening Width
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Mat Opening Height
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Inner Frame (Glass) Width
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Inner Frame (Glass) Height
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Frame Perimeter
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Picture frames are measured by their inner opening — the space that holds the artwork or glass — not the outer edge. Measure the width and height of your artwork first, then add the mat width and frame border width on each side to determine the full outer frame dimensions.
A mat (or mount) is a decorative border placed between the artwork and the frame. It provides visual breathing room for the piece and protects the artwork from touching the glass. The mat width adds to the overall inner frame size, so you need to account for it when ordering a frame.
The inner frame dimension (also called the rabbet or sight size) is the opening that holds your artwork and glass. The outer frame dimension is the total visible size of the frame including the moulding border. Both measurements are important — inner for glass/mat cutting, outer for hanging and wall space planning.
Common standard frame sizes in inches include 4×6, 5×7, 8×10, 11×14, 16×20, and 24×36. In centimeters, popular sizes are 10×15, 13×18, 20×25, 28×35, and 40×50. Using a standard size is cheaper since pre-cut glass and mats are readily available.
A mat width of 2–3 inches (5–8 cm) works well for most standard prints and photos. Larger artwork benefits from wider mats (3–4 inches). A 'weighted' mat — slightly wider at the bottom — is a popular technique that makes the artwork appear optically centered.
The frame perimeter is calculated as (outer frame width + outer frame height) × 2. This tells you the total length of moulding needed. Always add 10–15% extra to account for mitered corners and cutting waste.
Yes. Simply enter your exact artwork dimensions, your desired mat width, and the width of the frame moulding. The calculator will output all the custom dimensions you need — inner opening, outer size, and perimeter — whether you are ordering from a framer or building the frame yourself.
The mat opening is typically cut slightly smaller than the artwork — usually about 0.25 inches (0.5 cm) smaller on each side — so the mat overlaps the artwork edges and holds it in place. This calculator shows the artwork dimensions as the mat opening reference; apply a small overlap reduction when ordering a cut mat.