How to Measure Picture Frame Size
Measure the artwork first. Frame listings usually refer to the nominal artwork size they hold, not the total outside dimensions of the frame moulding.
How to measure picture frame size correctly
Do you measure a picture frame from the inside or outside?
When choosing a frame for artwork, use the inside nominal size—the size of the artwork the frame is designed to hold—not the decorative outside edge. Outside dimensions vary with moulding width.
How to measure for a mat
Measure the artwork first, then decide the visible opening and border. The mat opening is usually slightly smaller than the artwork so the print cannot fall through. The mat's outside dimensions must match the frame's nominal size.
Example: a 16×20 print can go directly into a 16×20 frame, or into a larger frame with a mat designed around the 16×20 artwork.
Frame measuring FAQ
How do you measure picture frame size?
Measure the artwork width and height, then select the frame's nominal inside size. Do not use the outside decorative dimensions as the artwork size.
What size mat and frame for a 16×20 picture?
A 16×20 frame is the direct no-mat choice. With a mat, choose a larger frame and a mat whose opening is sized to overlap the 16×20 print slightly.
Does the frame opening equal the listed size exactly?
Not always. The visible opening is often slightly smaller because the frame lip holds the artwork. Check manufacturer specifications when exact visibility matters.