How to Scale a Document Between Paper Sizes
To print a page on a different paper size without cutting it off, scale it by the smaller of the width ratio and the height ratio. This guide lists the exact percentages between A5, A4, A3, Letter and Legal.
| From → to | Scale |
|---|---|
| A5 → A4 | 141.4% |
| A5 → A3 | 200.0% |
| A5 → Letter | 133.0% |
| A5 → Legal | 145.9% |
| A4 → A5 | 70.5% |
| A4 → A3 | 141.4% |
| A4 → Letter | 94.1% |
| A4 → Legal | 102.8% |
| A3 → A5 | 49.8% |
| A3 → A4 | 70.7% |
| A3 → Letter | 66.5% |
| A3 → Legal | 72.7% |
| Letter → A5 | 68.6% |
| Letter → A4 | 97.3% |
| Letter → A3 | 137.6% |
| Letter → Legal | 100.0% |
| Legal → A5 | 59.1% |
| Legal → A4 | 83.5% |
| Legal → A3 | 118.1% |
| Legal → Letter | 78.6% |
The formula
To fit a page of width W and height H onto paper of width w and height h without cropping, use the smaller of two ratios: scale = min(w ÷ W, h ÷ H). The page is then as large as it can be while still fitting entirely on the sheet. Because ISO sizes share one aspect ratio, scaling between them is about 70.7% going down one size and about 141.4% going up one size. The exact fit-to-page figure can differ by a few tenths of a percent (for example A4 to A5 is 70.5%) because the official sizes are rounded to whole millimetres.
Why A4 and Letter need a different scale
A4 and Letter do not share an aspect ratio. A4 is narrower and taller, so scaling an A4 page onto Letter is limited by the height: it must be reduced to about 94.1%. Scaling Letter onto A4 is limited by the width and comes to about 97.3%.
How to use it in a print dialog
- Choose the paper size that is actually loaded in the printer.
- Pick the option often called "Fit to page" or "Scale to fit paper size" so the program calculates the scale for you.
- Use "Actual size" (100%) only when the page and the paper are the same size.
- Print one test page and check the edges before printing many copies.
Check the margins
Most printers cannot print to the very edge of the sheet, so a small unprintable margin is normal. If a scaled page still loses its edges, reduce the scale a little or increase the page margins in the original document.
Frequently asked questions
How do I scale A4 to A5?
Scale to 70.5%. A5 is half of A4, so the page keeps almost exactly the same shape; the figure is a little below the theoretical 70.7% because the official sizes are rounded to whole millimetres.
How do I scale A3 to A4?
Scale to 70.7%. A4 is half of A3.
How do I scale A4 to Letter?
Scale to about 94.1% so the whole page fits the shorter Letter sheet.
Related
- A4 vs Letter: What Is the Difference?Side-by-side comparison
- A4 Paper Size210 × 297 mm
- Letter Paper Size8.5 × 11 in
- Paper Size Converter: mm, Inches and PixelsAny size, any PPI
Last updated: 2026-10-03