What Size Should an Ebook PDF Be?

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 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. See the 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 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 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 works the same way. A PDF keeps a fixed page layout. For a paperback on 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.

How do I make an ebook at the right size?

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