Size Guide
Picking a frame comes down to two numbers: the size of the frame, and — if it has a mat — the size of the opening cut into that mat. This page explains how they relate, how to measure, and which sizes pair with which.
Frame size vs. mat opening
Frame size is the size of the frame — what the piece measures on your wall.
Mat opening is the window cut in the mat — the size of the artwork it displays.
On a matted frame these are two different numbers, and the mat opening is the one that has to match your art. A 16x20 frame with a 12x16 mat hangs as a 16x20 piece and displays a 12x16 print.
Two things worth knowing:
- The mat overlaps the edge of your print by about ¼ inch on each side, so nothing shows through the gap. Order the mat opening that matches your print size — don't size down for the overlap.
- Most matted frames can be used without the mat. Lift it out and the frame displays a print at its full frame size — so a 16x20 matted frame also works as a plain 16x20.
Which mat goes with which frame
These are the standard pairings across our matted collections. Some frames offer more than one mat option — the product page lists every combination available for that frame.
| Frame size | Standard mat opening | Also available |
|---|---|---|
| 5x7 | 4x6 | — |
| 6x6 | 4x4 | — |
| 6x8 | 4x6 | 3x5 |
| 8x8 | 6x6 | 5x5 |
| 8x10 | 5x7 | — |
| 9x12 | 6x8 | 6x6 |
| 10x10 | 8x8 | 4x4 |
| 11x14 | 8x10 | 8x11 |
| 12x12 | 8x8 | — |
| 12x16 | 8x12 | 4x6 |
| 13x16 | 9x12 | 10x13 |
| 14x18 | 10x14 | 5x7 |
| 15x15 | 12x12 | — |
| 16x20 | 12x16 | 11x14, 8x10, 6x8 |
| 16x24 | 12x18 | 8x12, 8x10 |
| 17x23 | 13x19 | — |
| 18x24 | 14x20 | 9x12, 8x10 |
| 20x24 | 16x20 | — |
| 20x28 | 16x24 | — |
| 22x28 | 18x24 | 12x16, 11x17 |
| 24x30 | 20x26 | 13x19, 14x17, 9x12 |
| 24x34 | 20x30 | — |
| 26x32 | 22x28 | — |
| 28x34 | 24x30 | — |
| 28x40 | 24x36 | — |
The pattern behind the table: the standard mat opening is roughly 4 inches smaller than the frame in each direction — about a 2-inch mat border all round. A wider border (a smaller opening in a larger frame) gives a more gallery-like look; that's what the "also available" options are for.
How to measure
- Measure the artwork, not the wall. Measure the print itself, edge to edge, in inches.
- Decide matted or unmatted. Unmatted, buy a frame in your print's exact size. Matted, buy a frame whose mat opening is your print's size.
- Check the outer dimensions. The size in the product name is the frame size — the outer edge measures slightly larger because the moulding sits outside it. Exact outer dimensions and depth are in the Product Details section of every product page.
- Watch the moulding width on posters. If your poster has text or a signature close to the edge, check the moulding width — a wide moulding will overlap the outermost part of the print. Moulding width is listed on the product page.
Standard print & poster sizes
If you're printing artwork to fit a frame you already have, these are the sizes to print at.
| Use | Common sizes (inches) |
|---|---|
| Photo prints | 4x6, 5x7, 8x10, 11x14, 16x20, 20x24, 24x30 |
| Square / social prints | 4x4, 6x6, 8x8, 10x10, 12x12, 20x20, 24x24 |
| Posters | 11x17, 12x18, 18x24, 24x36, 27x40 |
| Documents & certificates | 8.5x11 (US Letter), 11x14 |
| A-sizes | A4 (8.3x11.7), A3 (11.7x16.5), A2 (16.5x23.4) |
A note on 8.5x11: US Letter documents and diplomas are 8.5x11, which is not the same as an 8x10 photo. If you're framing a certificate, look for a frame or mat opening listed as 8.5x11.
Choosing a size for your wall
- Above furniture — aim for a piece, or an arrangement, about two-thirds the width of the sofa, bed or console beneath it.
- Hanging height — centre the piece at eye level, roughly 57–60 inches from the floor to the middle of the frame. Hang lower above furniture so the frame relates to the piece below it.
- Small art, big wall — a wider mat is the fix. A generous mat in a larger frame gives a small print presence without enlarging the art.
Gallery walls
Our frames are built with matching outer dimensions across sizes within a collection, so a multi-frame wall lines up cleanly rather than drifting out of alignment.
- Lay it out on the floor first. Arrange the whole set before you put a single nail in the wall.
- Keep the gaps consistent — 2 to 3 inches between frames reads as deliberate; anything uneven reads as a mistake.
- Mix sizes, keep one thing constant. Either one colour across mixed sizes, or one size across mixed colours. Varying both at once rarely works.
- Pre-built sets take the guesswork out — see Gallery Wall Sets.
Still not sure?
Tell us the size of your artwork and where it's going, and we'll tell you what to order. Email help@americanflat.com or use our contact form. We answer messages Monday to Friday and aim to reply within one business day.
See also: FAQ · Shipping Policy · Return & Refund Policy