- Use the size that is in your tray: Letter (8.5x11 in) in the US and Canada, A4 (210x297 mm) almost everywhere else.
- A4 is a little narrower and taller than Letter, so a mismatch clips or shrinks the grid.
- The fix is always to match the print dialog's paper size to the file, not to force one onto the other.
- Most calendar files here come in both sizes, so you rarely have to convert at all.
A4 and Letter look like the same sheet until you print a calendar sized for one on the other. Then a strip goes missing or the whole grid shrinks and floats in the middle of the page. The two formats are close, but close is exactly what causes the trouble.
The good news is that picking the right one is simple once you know the difference and how your printer handles a mismatch. Here is the short version for anyone printing calendars at home.
The actual difference between them
Letter measures 8.5 by 11 inches, which is 216 by 279 mm. A4 measures 210 by 297 mm, or about 8.27 by 11.69 inches. So A4 is roughly 6 mm narrower and 18 mm taller than Letter. That is small in the hand but enough to matter for a full-page grid.
The reason it bites is the aspect ratio. Letter is a bit wider and shorter; A4 is a bit slimmer and longer. A grid drawn to fill one shape will never perfectly fill the other, so something has to give at the edges when the sizes do not match.
A quick side by side
Here is how the two formats compare at a glance:
| Detail | Letter | A4 |
|---|---|---|
| Inches | 8.5 x 11 | 8.27 x 11.69 |
| Millimeters | 216 x 279 | 210 x 297 |
| Common in | US, Canada, Mexico | Most of the rest of the world |
| Shape | Wider, shorter | Narrower, taller |
| Fits the other tray | Not exactly | Not exactly |
Neither size is better for calendars. What matters is that the file and the paper in your tray agree.
What goes wrong when they do not match
Send a Letter file to A4 paper and the printer usually keeps the width but has extra height to spare, so you get a taller margin at the bottom and, if the design runs wide, a clipped left or right edge. Send an A4 file to Letter paper and the opposite happens: the taller A4 grid gets its top or bottom row cut, or the printer shrinks everything to fit and leaves uneven white borders.
Either way the symptoms are the same ones people blame on the printer: a missing strip, a floating grid, or a page that prints smaller than expected. It is almost never the printer. It is a size mismatch between the file and the tray.
How to match them the right way
Fixing it takes ten seconds in the print dialog. First, check what paper is actually loaded. Then set the dialog's Paper size to the same thing, and set Scale to 100% or Actual size so the grid is not silently shrunk. If the file and the paper genuinely differ and you cannot swap the paper, choose Fit to printable area, which scales the page down just enough to avoid clipping at the cost of a slightly smaller grid.
The cleaner route is to skip the mismatch entirely. Download the calendar in the size you use, so a US printer gets Letter and an A4 printer gets A4. The general printing guide walks through the exact dialog settings, and the Letter vs A4 paper size guide goes deeper on when to scale and when not to.
Which size to pick for a home calendar
Pick whichever size matches the paper you buy and the tray you load. In the United States, Canada, and Mexico that is Letter. Across Europe, the UK, Australia, Asia, and most other places it is A4. There is no quality gain from choosing the format your printer does not stock, only headaches.
If you share files with someone abroad, hand them the version for their paper rather than making them scale yours. Many calendars on this site, including the full-year 2026 calendar, come in both sizes, so pick the matching one and print at 100%.
So A4 or Letter
There is no winner in the abstract. The right size is simply the one in your printer. Match the file to that, keep the scale at 100%, and both formats produce an identical, crisp calendar with even margins.
If you ever build your own layout, the calendar maker lets you choose the paper size up front, so the file and your tray are guaranteed to agree before you ever open the print dialog.