Picture frame sizes: standard chart and how to measure

Picture frame sizes describe the artwork a frame is made to hold. In the US they are given in inches, width by height, so an 8 × 10 frame takes an 8 × 10 in print. The outside of the frame is bigger, and the part you actually see is a little smaller. Before you order, check which of those three numbers a listing gives.

This guide covers standard photo, document and poster sizes, the A sizes used in most of the world, how mats change the math, and how to measure so the first frame you buy fits.

Standard picture frame sizes chart

These are widely used US print, paper and poster sizes. Metric figures are direct conversions, rounded to the nearest millimeter. Shape is the long side divided by the short side.

The photo sizes (4 × 6, 5 × 7, 8 × 10, 11 × 14, 12 × 16, 16 × 20 and 20 × 24) all appear in the table of common print sizes in Wikipedia’s photo print sizes article. The 8.5 × 11 and 11 × 17 sizes are US paper sizes (Letter and ANSI B), and 12 × 18, 18 × 24 and 24 × 36 match the architectural sheet sizes Arch B, C and D, according to Wikipedia’s paper size article.

Poster sizes, including the 27 × 40 movie one-sheet

Many posters sold in the US are printed on the standard sheet sizes in the chart: 11 × 17, 12 × 18, 18 × 24 and 24 × 36 in. Film posters have their own formats, listed in Wikipedia’s film poster article:

• One-sheet, 27 × 40 in, portrait. The standard US theatrical poster.
• Older one-sheet, 27 × 41 in. One inch longer; this size was phased out in the mid-1980s, so measure vintage posters before ordering a frame.
• Half-sheet, 22 × 28 in, landscape, and insert, 14 × 36 in, portrait. Both older US formats.
• UK quad, 30 × 40 in, landscape.

Double-sided posters, printed for light boxes, have a mirror image on the back. Our double-sided movie poster guide covers why that matters once the poster is lit. The Lumi Frames Lightbox comes in 12 × 18, 16 × 24, 24 × 36 and the 27 × 40 in one-sheet size.

ISO A sizes in inches (A4 to A1)

Outside North America, paper, and with it many prints and posters, comes in ISO 216 A sizes. Wikipedia’s ISO 216 article notes that the standard is used around the world except in North America, the Philippines and parts of Latin America. Every A size has the same shape, a ratio of 1 to the square root of 2 (about 1.41), and each size is half the area of the one above it.

Because the A shape sits between 4:3 and 3:2, none of the US sizes in the chart match it exactly. A frame sold in A sizes, or a larger frame with a mat cut to the print, is the tidy fix.

Frame size, visible area and outer dimensions

Every frame has three sizes, and product listings do not always say which one they mean.

• Frame size is the opening at the back, in the recess called the rabbet, which holds the glazing, mat, artwork and backing. It is the number the frame is sold by. Openings are made with a little play; the Northeast Document Conservation Center’s matting and framing leaflet suggests the mat and backing fit the frame with 1/16 to 1/8 in of total wiggle room.
• Visible area is what you see from the front. The frame’s lip, or a mat window, overlaps the edges of the print, so keep signatures and important details away from the very edge.
• Outer dimensions are the frame size plus the moulding width on each side. Use them when you plan a gallery wall or check that a frame fits between a window and a shelf.

For illuminated frames, the light itself can add to the outside or the depth, so check whether a listed size refers to the artwork or the whole frame. To see where the LEDs sit in each design, read what an illuminated frame is.

Aspect ratio: why some photos don’t fit

Two frames can be close in size but different in shape, and shape decides whether a photo fits without cropping. According to Wikipedia’s article on image aspect ratio, 35 mm film and its digital descendants shoot 3:2, most compact digital cameras shoot 4:3, and the 5:4 shape fits an 8 × 10 print without cropping.

• 3:2 photos enlarge cleanly to 4 × 6, 12 × 18, 20 × 30 and 24 × 36.
• 4:3 photos fit 12 × 16 and 18 × 24.
• 5:4 frames (8 × 10 and 16 × 20) crop a 3:2 photo. As the diagram shows, an 8 × 12 print trimmed to 8 × 10 loses a sixth of its height.

You have three ways around a mismatch: crop the image when you order the print, print it smaller on a sheet with a white border, or use a mat whose window is cut to the photo’s true shape.

Mats: going one frame size up

A mat does two jobs. It keeps the print from touching the glazing, which NEDCC says objects should never do, and it gives the image breathing room. A matted print goes in a frame one or two sizes larger than the print itself: an 8 × 10 in an 11 × 14 frame is the classic pairing.

The mat’s window is cut slightly smaller than the print so the mat holds its edges. For example, an 8 × 10 print might get a 7.5 × 9.5 in window. Some framers give the bottom border a little extra width, called a bottom-weighted mat, which can make the image look better centered.

In a backlit or edge-lit frame, an opaque mat blocks the light behind it and reads as a dark border, so it usually makes sense to print the image to fill the whole opening. See edge-lit vs backlit frames for how those designs spread light.

How to measure for a frame

1. Measure the artwork, width first, then height, to the nearest 1/8 in. Measure each dimension in two places, since paper is not always perfectly square.
2. Decide what should show: the whole image to the edge, or the image with a mat border.
3. Add the border. For a mat, add twice the border width to each dimension. An 8 × 10 print with a 7.5 × 9.5 in window in an 11 × 14 frame gets borders of 1.75 in at the sides and 2.25 in at the top and bottom.
4. Round up to a standard size and adjust the border to suit, or order a custom frame.
5. Measuring an existing frame? Take it off the wall and measure the opening at the back, not the visible window at the front or the outside edge.
6. Check the outer dimensions against the wall space and any furniture below.
7. For a lit frame, plan the power. Note where the cord will run; our guide on hiding the cord for a light-up frame helps.

Sizes for illuminated frames

Lit frames follow the same standards. The Lumi Frames Edge comes in 5 × 7, 8 × 10 and 11 × 14 in for standard photo prints. The Lumi Frames Neon comes in 26 sizes from 8 × 8 to 24 × 36 in, including square sizes for square prints. Jersey display cases are sized differently; see our jersey frame size guide.