The quickest way to adjust text size on any Kindle
On any Kindle device or app, you change font size by opening a book, then pressing the Aa button (or icon) that appears on the screen. A menu will pop up with a slider showing font sizes from smallest to largest. Move the slider to the size you want, then tap outside the menu to close it. The change takes effect immediately and stays set for that book.
The exact location of the Aa button depends on which Kindle you own — on e-ink devices like the Paperwhite or Oasis it's at the top of the page, while in the Kindle app on phones or tablets it's usually in the top menu bar. But the process is the same across all of them.
Key Takeaways
- Press or tap the Aa button while reading to open the font size menu, then drag the slider to your preferred size.
- Font size changes apply only to the book you're currently reading — each book remembers its own setting.
- Changing font size does not affect how many pages a book shows it contains, because Kindle counts pages based on the original file, not your display settings.
- If you cannot find the Aa button, swipe down from the top of the screen on tablets or phones, or look at the top toolbar on e-ink devices.
Where to find the font size button on different Kindle devices
On Kindle e-ink devices (Paperwhite, Oasis, Keyboard, Basic), the Aa button sits in the toolbar at the top of the page. Tap it once and the font menu appears below it. If you do not see a toolbar, tap the middle of the screen — the toolbar will appear.
On the Kindle app for iPhone or iPad, swipe down from the top of the screen or look for the menu icon (three horizontal lines) in the top right corner. The Aa button is usually there. On some older versions of the app, you may need to tap the screen first to reveal the menu bar.
On the Kindle app for Android phones and tablets, tap the screen to reveal the menu bar at the top, then look for the Aa button. On Kindle for Mac or Windows, the Aa button is in the top toolbar of the reading window.
What happens when you change font size
When you increase the font size, the text becomes larger and fewer words fit on each screen. You will turn pages more often. When you decrease it, more text fits on the screen and you turn pages less often. Kindle reflows the text automatically — it does not just zoom in on a fixed page.
Each book remembers the font size you set for it. If you read one book at size 5 and another at size 3, Kindle will open each one at the size you last used. This means you can have different books set to different sizes without having to change the setting every time you switch books.
Font size and page count — why the numbers seem wrong
Kindle shows a page count for each book based on the original file, not on your current font size setting. If a book says it has 300 pages and you increase the font size to the largest setting, you might actually turn 450 pages to finish it. The page count does not change because Kindle counts pages the way the publisher submitted them, not the way they appear on your screen.
This also means your reading progress percentage is based on the original page count. If you are at 50% of the book according to Kindle, you are halfway through the content, even if your screen shows a different number of pages than someone else reading at a smaller font size.
Other text settings that work alongside font size
The Aa menu also contains other options beyond just size. You can usually adjust line spacing (how much room sits between lines of text), margins (how much blank space sits on the left and right edges), and sometimes font choice (which typeface the text uses). These settings work together with font size to change how the page looks.
On e-ink Kindles, you may also see an option for bold text, which makes every letter thicker and darker. This can help if you find regular text hard to read, though it does make the text take up more space on the screen.
What to do if the Aa button is not visible
On e-ink devices, tap the middle of the screen. The toolbar should appear at the top. If it does not, you may be in a menu or a book that does not support font adjustment (very rare, usually only in some PDFs or fixed-layout books).
On phone or tablet apps, make sure you are actually inside a book and not on the library screen. Swipe down from the very top of the screen or tap the menu icon. If you still cannot find it, close the app completely and reopen it — sometimes the menu bar gets stuck.
If you own a very old Kindle (more than ten years old), the button location or name may be different. Check the device manual or search the Kindle support site for your specific model number.
Font size for different types of books
Regular e-books (the kind Kindle was built for) respond perfectly to font size changes. The text reflows and you can set it to any size you want. Fixed-layout books — usually graphic novels, children's books, or art books — do not reflow. These books have a set page design, so changing font size may zoom in on a fixed page instead of reflowing text. You can still zoom in and out, but it works differently than with regular e-books.
PDFs behave like fixed-layout books. You can zoom in to read them larger, but the text does not reflow. If you have a PDF on your Kindle and the text is too small, zooming is your only option.
Frequently Asked Questions
Does changing font size affect how long it takes to read a book?
No, it does not change the actual content. A larger font size means you turn pages more often, but you are reading the same number of words. The time it takes depends on your reading speed, not on the font size you choose.
Will my font size setting stay the same if I delete and re-download a book?
No. When you delete a book from your device, Kindle forgets the font size you set for it. If you download it again later, it will open at the default size. Your bookmarks and notes stay in the cloud, but display settings do not.
Can I set a default font size for all my books?
Not directly. Kindle does not have a global default setting. However, the first book you open after restarting your device will use whatever size you last set, and new books will often open at a middle size. You can change each book individually as you read it.
What is the largest font size available?
Kindle offers several font sizes, usually labeled 1 through 7 or 8, with 1 being smallest. The largest size varies slightly by device, but it is large enough that only a few words fit on each line. If even the largest size is too small, check whether your device has a bold text option, which can make text easier to read.
Does font size work the same way on the Kindle app and on Kindle devices?
The process is the same — find the Aa button and use the slider — but the location of the button differs. The range of available sizes may also vary slightly between the app and e-ink devices, though most people will not notice the difference.