Side by side
| Size | Inches | Millimetres | Used in |
|---|---|---|---|
| US Letter | 8.5 × 11 | 215.9 × 279.4 | US and Canada |
| A4 | 8.27 × 11.69 | 210 × 297 | Most other countries |
A4 is 5.9 mm narrower and 17.6 mm taller than US Letter. A4 belongs to the ISO 216 A series, where each size is half the one before it.
Why it matters for printables
A sheet designed for one size and printed on the other gets cropped or shrunk to fit. Choose the paper size that matches what is in your printer before you download; the graph paper generator offers both. Then print at actual size, not “fit to page”.