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A4 vs Letter Size: A4 Is 0.23 in Narrower and 0.69 in Taller
The two sheets compared
-
ISO 216
A4 paper
8.27 × 11.69 in (210 × 297 mm)
-
ASME Y14.1 (ANSI A)
US Letter paper
8.5 × 11 in (215.9 × 279.4 mm)
The short answer
- A48.27×11.69 in (210×297 mm)
- Letter8.5×11 in (8 1/2×11 in / 215.9×279.4 mm)
- DifferenceA4 is 0.23 in (5.9 mm) narrower and 0.69 in (17.6 mm) taller
See the sizes in AR (shown as boxes)
The two sizes as boxes at their published dimensions
Preparing 3D…
1 A42 Letter
On a phone, the "View in your room (AR)" button places the boxes in your room. The boxes are locked to the published dimensions and cannot be resized. They show size only and are not 3D replicas of the products.
Drawn to the same scale
Dimensions side by side
| Item | A4 | Letter | Difference |
|---|---|---|---|
| Width | 8.27 in / 210 mm | 8.5 in / 215.9 mm (8 1/2 in) | A4 is 0.23 in (5.9 mm) narrower |
| Height | 11.69 in / 297 mm | 11 in / 279.4 mm | A4 is 0.69 in (17.6 mm) taller |
| Area | 96.7 in² / 623.7 cm² | 93.5 in² / 603.2 cm² | A4 is 3.4% larger |
| Aspect ratio | 1 : 1.414 | 1 : 1.294 | A4 is longer and thinner |
Inches for A4 and millimeters for Letter are converted at 1 in = 25.4 mm and rounded.
Pixels and points
| Size | 150 dpi | 300 dpi | 600 dpi | Points (pt) |
|---|---|---|---|---|
| A4 | 1240 × 1754 px | 2480 × 3508 px | 4961 × 7016 px | 595 × 842 pt |
| Letter | 1275 × 1650 px | 2550 × 3300 px | 5100 × 6600 px | 612 × 792 pt |
Pixel counts are the inch dimensions multiplied by the dots per inch and rounded to whole pixels (A-series sizes are defined in millimeters and divided by 25.4 first). They say how many pixels fill the sheet at that density, not what any printer or service requires. Points are 1/72 in, the unit page-layout and PDF software uses for page size.
What the numbers mean
Neither sheet contains the other. Letter is wider, A4 is taller, so a page laid out for one size does not fit the other at 100%.
An A4 layout on Letter paper loses 0.69 in (17.6 mm) at the bottom. Scaling to 94% (279.4 ÷ 297) fits it. A Letter layout on A4 paper loses 0.23 in (5.9 mm) on the right. Scaling to 97% (210 ÷ 215.9) fits it.
A4's 1 : √2 ratio is why two A4 sheets side by side make exactly one A3. Letter does not halve or double into the same shape.
Product links
FAQ
What is the difference between A4 and Letter size?
A4 is 8.27×11.69 in (210×297 mm). US Letter is 8.5×11 in (215.9×279.4 mm). A4 is 0.23 in (5.9 mm) narrower and 0.69 in (17.6 mm) taller than Letter.
Will an A4 document fit on Letter paper?
Not at 100% scale. A4 is 0.69 in (17.6 mm) taller than Letter, so the bottom of an A4 layout falls off a Letter sheet unless you scale it down, for example to about 94%.
Will a Letter document fit on A4 paper?
Not at 100% scale. Letter is 0.23 in (5.9 mm) wider than A4, so the right edge of a Letter layout falls off an A4 sheet unless you scale it down, for example to about 97%.
Which countries use Letter instead of A4?
Letter is the standard office size in the United States and Canada. Most other countries use A4 from ISO 216.
See also: Tabloid (11x17) vs A3 — the same ANSI series one step larger. ANSI Paper Sizes A–E — all five ANSI sizes drawn to the same scale. iPhone 17 lineup sizes — all four models drawn to the same scale.
Sources
- A4: ISO 216 (A series), 210×297 mm. Japan's JIS P 0138 uses the same value.
- Letter: ASME Y14.1 defines ANSI A as 8.5×11 in, modeled on Letter (ANSI Blog, "Standard Paper Sizes – ISO and ANSI Formats", checked 2026-09-26).
- Credit card: ISO/IEC 7810 ID-1, 85.60×53.98 mm (rounded to 85.6×54 mm in the figure caption).