# What Size Should an Ebook PDF Be?

> Use US Letter (8.5 × 11 in) or A4 for ebooks people read on screen or print at home, and 6 × 9 in for book-style ebooks and paperbacks. Keep the file small enough to email, with fonts embedded.

Source: https://buildpdfs.com/guides/what-size-should-an-ebook-pdf-be
Published: 2026-10-10

**For most ebook PDFs, use US Letter (8.5 × 11 in) if your readers are in the US or Canada, or A4 (210 × 297 mm) for the rest of the world.** If the ebook should feel like a book, or you also plan a paperback, use 6 × 9 in.

"Size" can mean three things: the page size, the file size and the font size. This page covers all three.

## Which page size should I use?

| Page size | Inches | Millimeters | Best for |
|---|---|---|---|
| US Letter | 8.5 × 11 | 216 × 279 | Lead magnets, guides and workbooks for US and Canadian readers |
| A4 | 8.27 × 11.69 | 210 × 297 | The same uses, for readers outside North America |
| 6 × 9 | 6 × 9 | 152 × 229 | Book-style ebooks and nonfiction paperbacks |
| 5.5 × 8.5 | 5.5 × 8.5 | 140 × 216 | Novels and shorter books |

Pick the size your reader will print on. A guide with checklists or worksheets gets printed, so Letter or A4 is the safe choice. A narrative ebook is mostly read on screen, where a 6 × 9 page is close to the shape of a tablet or phone held upright.

If you plan to sell a paperback too, choose the [trim size](/glossary#trim-size) first and design the ebook at the same size. Then one layout serves both. BuildPDFs makes book interiors at 6 × 9 and 5.5 × 8.5 with [mirrored margins](/glossary#mirrored-margins). See the [AI book formatter](/ai-book-formatter).

## How big should the file be?

Smaller is better for downloads and email. As a guide:

- **Under 10 MB** for a lead magnet that you send by email or link from a landing page.
- **Under 20 MB** for a long ebook with many images.
- Many email services refuse attachments over about 20–25 MB, so link to large files instead of attaching them.

Images make most of the file size. Use about 150 [DPI](/glossary#dpi) for screen-only ebooks and about 300 DPI for ebooks that people will print. Save photos as JPG and logos as SVG or PNG.

## What font size should an ebook use?

- **US Letter or A4:** body text of 11–12 pt, headings 18–28 pt.
- **6 × 9 or 5.5 × 8.5:** body text of 10–12 pt.
- **Line spacing:** about 1.3 to 1.5 times the font size.
- **Fonts:** use one or two typefaces, and make sure they are [embedded](/glossary#embedded-fonts) in the PDF, so the text looks the same on every device.

## FAQ

### Is A4 or Letter better for an ebook?

Neither is better in general. Use the size your readers print on: Letter in the US and Canada, A4 almost everywhere else. If you sell worldwide, you can export the same ebook in both sizes.

### What size is a Kindle ebook?

Most Kindle ebooks are reflowable: the text adapts to the screen, so there is no fixed page size. An [EPUB](/glossary#epub) works the same way. A PDF keeps a fixed page layout. For a paperback on [KDP](/glossary#kdp), 6 × 9 in is a common trim size for nonfiction.

### How many pages should an ebook be?

That depends on the purpose. See [how long should an ebook be](/guides/how-long-should-ebook-be).

### How do I make an ebook at the right size?

Describe your ebook to the [AI ebook generator](/ai-ebook-generator) or start from the [minimal ebook template](/templates/ebook-minimal), choose the page size, and export a print-ready PDF. For a book interior, use the [self-published book template](/templates/self-published-book) at 6 × 9.