Guides · Printing and framing
A3 vs 11x17: what's the difference, and which frame fits A3?
A3 is 297 × 420 mm (11.69 × 16.54 in); 11x17, US tabloid, is 11 × 17 in (279.4 × 431.8 mm). A3 is 17.6 mm wider and 11.8 mm shorter, so neither fits the other's frame. Put an A3 print in an A3 frame (29.7 × 42 cm), or a larger frame with a mat cut for A3.
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How big are A3 and 11x17?
A3 is an ISO 216 size, used in most of the world: two A4 sheets side by side. 11x17, called tabloid (or ledger when turned sideways), is the US equivalent: two Letter sheets. Side by side:
| Measure | A3 | 11x17 |
|---|---|---|
| Millimetres | 297 × 420 mm | 279.4 × 431.8 mm |
| Inches | 11.69 × 16.54 in | 11 × 17 in |
| Shape | 1:√2 (0.707) | 11:17 (0.647) |
| Area | 1,247 cm² | 1,206 cm² |
| Pixels at 300 DPI | 3,508 × 4,961 px | 3,300 × 5,100 px |
| Pixels at 150 DPI | 1,754 × 2,480 px | 1,650 × 2,550 px |
| Made of | 2 × A4 | 2 × US Letter |
Which frame fits an A3 print, and which an 11x17?
A frame takes a print that is the same size or up to about 2 mm bigger (the frame's lip covers that). More than that and the print won't go in; much smaller and it slides around or shows the backing, so it needs a mat. Without a mat:
| Frame | A3 print (297 × 420 mm) | 11x17 print (279.4 × 431.8 mm) |
|---|---|---|
| A3 frame (29.7 × 42 cm) | Fits exactly | No: 11.8 mm too long |
| 11 × 17 in frame | No: 17.6 mm too wide | Fits exactly |
| 30 × 40 cm frame | No: 20 mm too long | No: 31.8 mm too long |
| 12 × 16 in frame | No: 13.6 mm too long | No: 25.4 mm too long |
| 30 × 45 cm frame | Loose: up to 30 mm short, so use a mat | Loose: up to 20.6 mm short, so use a mat |
| 12 × 18 in frame | Loose: up to 37.2 mm short, so use a mat | Loose: up to 25.4 mm short, so use a mat |
Which larger frames take A3 with a mat?
A mat (passe-partout) cut for the print overlaps it by about ¼ in (6 mm) on each side, so the window is a little smaller than the print. In a larger frame that leaves these borders, given as sides · top and bottom:
| Frame | A3 window | A3 borders | 11x17 window | 11x17 borders |
|---|---|---|---|---|
| 40 × 50 cm | 284 × 407 mm | 58 · 46 mm | 267 × 419 mm | 67 · 40 mm |
| 16 × 20 in | 284 × 407 mm | 61 · 50 mm | 267 × 419 mm | 70 · 44 mm |
| 18 × 24 in | 284 × 407 mm | 86 · 101 mm | 267 × 419 mm | 95 · 95 mm |
| 50 × 70 cm | 284 × 407 mm | 108 · 146 mm | 267 × 419 mm | 117 · 140 mm |
What happens if you print one on the other's paper?
Printed at its own size (100%) on 11x17 paper, an A3 file is 17.6 mm too wide, so the sides are cut. With “Fit to page” it shrinks to about 94%, 11 × 15.6 in, with white space at the top and bottom. An 11x17 file on A3 paper is the other way round: at its own size (100%) it is 11.8 mm too tall, and Fit to page shrinks it to about 97%. For a sharp edge-to-edge print, use a file made for the paper, or crop: an A3 image filling 11x17 loses 8% of its width.
Is a phone photo big enough for A3 or 11x17?
A 12 MP phone photo (4,032 × 3,024) gets about 244 DPI at A3 and 237 DPI at 11x17 once cropped to fill: enlarged, a little softer up close, fine on a wall. For a sharp print at either size, the photo needs about the 300 DPI pixels in the table above. The print size calculator works it out for any image.
How to choose
- Measure the frame's opening or read its label: an A3 frame takes 29.7 × 42 cm, a tabloid frame 11 × 17 in.
- Print at that exact size. A file for the other paper needs cropping or scaling, as above.
- For a frame bigger than the print, use a mat cut for the print: the tables give the window and borders.
- Crop a photo to either size in Photo to Frame; both need a print shop or a printer that takes A3 or 11x17 paper. A4 and Letter are compared in A4 vs US Letter.
Frequently asked questions
Is A3 the same as 11x17?
No. A3 is 297 × 420 mm and 11x17 is 279.4 × 431.8 mm: A3 is 17.6 mm wider and 11.8 mm shorter, and a different shape (1:√2 against 11:17). They are close in area; A3 is about 3% bigger.
Will an A3 print fit an 11x17 frame?
No: it is 17.6 mm too wide for the frame and 11.8 mm short of its height. You could trim the sides and live with a gap, but an A3 frame, or a larger frame with a mat cut for A3, fits properly.
What size frame do I need for an A3 print?
An A3 frame (29.7 × 42 cm). Otherwise a 40 × 50 cm or 16 × 20 in frame with a mat cut for A3: the window is about 284 × 407 mm. A 30 × 40 cm frame is 20 mm too short for A3.
Can I print an A3 file on 11x17 paper?
Yes, with Fit to page: it prints at about 94%, 11 × 15.6 in, with white space at the top and bottom. At 100%, 17.6 mm of its width doesn't fit on the sheet.
How many pixels is A3 at 300 DPI?
3,508 × 4,961 pixels (297 × 420 mm ÷ 25.4 × 300). An 11x17 at 300 DPI is 3,300 × 5,100. At 150 DPI, the lowest that still looks acceptable from a step back, A3 needs 1,754 × 2,480.
Sources and how the numbers were worked out
Pixel, crop and size figures on this page are calculated from the same size data the FrameReady tools use (inches or millimetres × DPI), not copied from elsewhere.