Choosing the right 15×20 picture frame size comes down to one decision: whether you plan to display the print with a mat or without one. The frame size listed by retailers refers to the artwork it holds, not the outer dimensions of the frame itself, which trips up plenty of first-time buyers. Once you measure your print edge to edge and decide on matting, the right fit becomes straightforward.
What Does “15×20” Actually Mean?
The number on a frame listing is the size of the image or paper that fits inside the frame, not the physical outer measurement. A standard 15×20 frame is built to hold a print that is exactly 15 inches wide by 20 inches tall. This means a 15×20 frame is actually larger than 15 by 20 inches on the outside, with the difference determined by the molding width.
You’ll see this clearly when comparing products. One 15×20 frame, for example, measures 15.75 x 20.75 inches on the outside with 0.75-inch molding. Another 15×20 frame lists a finished size of 17 x 22 inches with wider 1.25-inch molding. Both are correctly labeled “15×20” because both accept a 15×20 print. The outside dimensions differ because the frames use different molding widths.
Mat or No Mat? That Decides the Size
Without a mat, the frame opening should match your artwork exactly. Measure the print edge to edge, excluding any borders. If that measurement is 15 x 20 inches, a standard 15×20 frame gives you a clean, gap-free fit. This is the simplest scenario: buy the frame size that matches the print.
With a mat, the frame must be larger than the print. The mat’s opening is smaller than the artwork so the print rests behind it without falling through, and the mat border itself needs space around the image. So a 15×20 print with a mat typically needs a frame in the next size up, such as an 18×24.
This is the most common mistake buyers make. They pick a 15×20 frame for a 15×20 print and expect to add a mat later. It does not work — the print would cover the entire opening with no room for a mat border.
Check Aspect Ratio and Thickness Before Buying
Your print’s proportions must match the frame’s proportions. If your artwork is 15 x 18 inches, for instance, forcing it into a 15×20 frame means cropping part of the image or leaving an unwanted gap on one side. Measure the print first and confirm the frame matches both dimensions, not just one.
Thickness matters less often but still deserves a check. Product listings specify a maximum insert thickness, which includes the print plus any backing board. Most frames handle standard paper prints easily, but canvas prints or artwork mounted on thick boards can exceed the frame’s capacity.
The frame’s glass or acrylic also affects handling. Some 15×20 frames use UV acrylic instead of glass, which is lighter and less likely to break during shipping or hanging. Product pages typically note the glazing material, and most include foam board backing and hanging hardware in the box.
Measuring Your Artwork the Right Way
Take the measurement with a ruler along the longest edges of the print itself. Do not include any white border or decorative edge you plan to hide under the frame’s lip. If the print sits loose at 15 x 20 inches exactly, a standard 15×20 frame works. If the measurement falls slightly over — say 15.25 inches on one side — you need the next size up or a custom frame.
For matted displays, measure the print, then select a frame one standard size larger. The mat opening should be cut a quarter to half an inch smaller than the print on each side so the edges stay hidden and the artwork sits securely.
Frame sizing guides from Frame USA’s picture frame size guide and framing math resources confirm the same principle: the stated frame size refers to the artwork it holds, with matted displays requiring a larger frame than the print. For a quick reference, 15 x 20 inches converts to 38.1 x 50.8 centimeters, useful when ordering from international sellers.
When you are ready to buy, our tested roundup of the best 15 x 20 picture frames compares real products side by side so you can pick one that fits your print and your wall.
Before ordering, verify the frame’s overall dimensions on the product page. A quick check of the stated outside measurement prevents the surprise of a frame that looks larger or smaller than expected on the wall.
References & Sources
- Frame USA. “Picture Frame Sizes.” Explains that listed frame sizes refer to artwork dimensions, not outer measurements.
- Framing Math. “Standard Frame Sizes.” Details how matting requires a larger frame than the print size.
