A4 or Letter: choose the paper before the layout
A4 and US Letter look similar on a screen. Their dimensions are different enough to change what fits—and to make a printer resize a page.
The dimensions used in the tool
| Paper | Portrait width | Portrait height |
|---|---|---|
| A4 | 210 mm | 297 mm |
| US Letter | 215.9 mm (8.5 in) | 279.4 mm (11 in) |
Letter is wider; A4 is taller. Landscape swaps the width and height. Select the sheet you will actually use before deciding on image sizes or quantity.
Margins reduce the usable area
With 10 mm margins, an A4 portrait sheet has a 190 × 277 mm usable area. A Letter portrait sheet has 195.9 × 259.4 mm. The same margins are applied on all four sides in the current tool.
Printer hardware can have asymmetric printable margins. If your printer needs more space on one side, choose a uniform margin large enough for that side or prepare a custom layout elsewhere. The browser cannot detect your printer’s physical limits.
Gaps count too
For a row of copies, the width is the sum of the image widths plus the gaps between them. There is no extra gap after the final copy. A 3 cm-wide frame with a 3 mm gap fits five times across a 190 mm area: five frames use 150 mm and four gaps use 12 mm.
Choose A4 portrait, 3 × 4 cm frames, 10 mm margins, a 3 mm gap and 30 copies. Five columns and six rows can fit, so all 30 copies fit on one sheet. The occupied grid is centered; it is not stretched to use spare space.
Avoid automatic resizing
The print sheet builder creates a document at the selected paper size. If you choose a different sheet in the print dialog, the browser or printer can scale the content. Use the matching paper and 100% scale, then measure a first copy.