Measure before entering numbers
Measure the usable area inside a frame or the clear wall space, not the outside of a decorative frame. Keep width and height in the same unit. A 60 cm width is 600 mm, not 60 mm.
If the original ratio differs from the target, choose between preserving the whole picture with blank space and cropping to fill. Stretch changes proportions and is usually unsuitable for faces or scale-sensitive templates.
Exact dimensions versus paper saving
Use exact dimensions when the poster must fit a measured place. Turn off paper saving and recheck the reported final width and height. A paper-saving result deliberately reduces the image to use a smaller complete grid.
For an informal wall decoration, a slightly smaller poster may save several sheets. For a ruler, map grid, sewing reference or a frame fit, reducing the dimensions can defeat the purpose.
Why the page count changes
Margins reduce the printable rectangle. Overlap repeats part of the picture across neighbours. Changing paper orientation changes both the usable width and height. Automatic orientation compares the candidate page counts, but you should still inspect the layout.
For a worked example, enter 60 × 90 cm in the calculator with A4, 10 mm margins and 5 mm overlap. Compare portrait, landscape and Auto using the displayed counts; then compare the smaller paper-saving result. Change just one setting at a time so you know what produced the difference.
Confirm before exporting
- Match paper size to the printer tray and check portrait/landscape orientation.
- Confirm the displayed finished width and height after any preset or saving option.
- Inspect crop and page boundaries; keep important details away from intentional divider bands.
- Check the total sheets against your available paper and export.
- Measure a test print at 100% before producing a dimension-sensitive poster.