US Letter vs A4
If you have ever printed a document and found it cut off or shrunk, paper size was probably the reason.
Print a calendar in Letter or A4Every printable tool here lets you choose US Letter or A4.
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The two sizes
- US Letter: 8.5 × 11 inches (216 × 279 mm). It is the main home and office size in the United States, Canada and the Philippines.
- A4: 210 × 297 mm (about 8.27 × 11.7 inches). Most other countries use it.
A4 is about 6 mm narrower and 18 mm taller than Letter.
Why A4 halves neatly
The A series follows a simple rule. Each sheet has a width-to-height ratio of 1 to √2 (about 1.414). If you cut a sheet in half across the middle of its long sides, each half keeps the same ratio. A0 is defined to have an area of 1 square meter, and each step down (A1, A2 and so on) halves the area. A4 is therefore almost exactly 1/16 of a square meter.
Where Letter came from
The exact origin of Letter's dimensions is unknown. One explanation, from the American Forest and Paper Association, links it to hand papermaking, where the 11-inch length was about a quarter of a papermaker's arm stretch. In the early 1980s Letter became the norm for US federal forms, replacing a smaller government size of 8 × 10.5 inches.
Printing tips
- Choose the paper size of the sheets you actually have loaded, in the tool and in the print window.
- Set scale to 100% or "actual size". "Fit to page" can shrink the page and change the spacing of lines and grids.
- If you must print a Letter page on A4, or the reverse, expect narrow margins in one direction.
Print a calendar in Letter or A4Every printable tool here lets you choose US Letter or A4.
Open the tool →
Sources
Checked on October 15, 2026. We summarize in our own words and only state what these sources support.
- Wikipedia: ISO 216 — A4 size, the square-root-of-2 ratio and countries
- Wikipedia: Letter (paper size) — Letter size, usage and history