Change font size in Outlook by selecting text and using the font size dropdown, or by adjusting your default font settings so every new message starts with your preferred size
The fastest way to change font size in a single message is to highlight the text you want to resize, then click the font size dropdown in the toolbar and pick a new size. If you want every message you write to start with a larger or smaller font, you can set a default in your account settings instead — this saves you from resizing text in every draft.
The steps differ slightly depending on whether you use Outlook on the web, Outlook desktop, or Outlook on your phone. The web and desktop versions give you the most control; mobile is more limited.
Key Takeaways
- Highlight text in any message and use the font size dropdown in the toolbar to change just that text without affecting the rest of the message.
- Set a default font size in Outlook settings so all new messages you compose start with your preferred size automatically.
- Outlook on the web and desktop let you change font size; the mobile app does not offer this feature.
- Changing your default font size does not affect messages you have already written or received.
Change font size in a single Outlook message
Open the message you are writing and highlight the text you want to resize. Click and drag to select the words, or triple-click to select an entire paragraph. Once the text is highlighted, look for the font size box in the toolbar — it usually shows a number like "11" or "12" next to a small dropdown arrow.
Click the dropdown arrow next to the font size number. A list of sizes will appear, ranging from small sizes like 8 or 10 up to larger sizes like 18, 24, or 28. Click the size you want. The selected text will resize immediately. You can resize different parts of the same message to different sizes if you need to — just select a new section and pick a different size.
Set a default font size for all new messages in Outlook desktop
Open Outlook and go to File in the top left corner. Click Options at the bottom of the menu. In the Options window, click Mail on the left side, then scroll down until you see Compose messages. Click the button that says Stationery and Fonts.
A new window will open with tabs at the top. Click the tab labeled Personal Stationery. Under "New mail messages," you will see a button that says Font. Click it. A font dialog will appear where you can choose your font and size. Select the size you want, then click OK twice to save your changes. Every new message you write from now on will start with that font size.
Set a default font size for all new messages in Outlook on the web
Sign into Outlook on the web and click the gear icon in the top right corner. Click View all Outlook settings. On the left side, click Mail, then click Compose and reply. Scroll down to find the Default font section.
Click the dropdown next to "Font" and select your preferred font. Then click the dropdown next to "Size" and choose your preferred size. Scroll to the bottom of the page and click Save. Your new default will apply to all messages you compose going forward.
Why you might want to change your default font size
If you find yourself resizing text in every message, setting a default saves time. Larger fonts are easier to read on screen and in printed emails, especially if you have vision concerns. Smaller fonts let you fit more text on screen without scrolling. Your default choice does not affect how recipients see your message on their end — their email client will display it based on their own settings and preferences.
Keep in mind that very large fonts can make your messages harder for others to read, and very small fonts may be difficult for recipients with vision challenges. A size between 11 and 14 is standard in most workplaces.
Change font size on Outlook mobile
The Outlook mobile app for iPhone and Android does not include a font size option in the compose screen. If you need to send a message with a specific font size, you will need to use Outlook on the web or desktop instead.
You can still control how large text appears when you are reading messages on your phone — your phone's display settings control the text size for all apps, including Outlook. This does not change the actual font size in the message itself, only how it looks on your screen.
Undo or reset your font size changes
If you changed the default font size and want to go back, return to the same settings menu where you made the change. In Outlook desktop, go back to File > Options > Mail > Stationery and Fonts > Personal Stationery > Font and select a different size. In Outlook on the web, go back to Settings > Mail > Compose and reply > Default font and pick a new size. Click Save.
For text you have already resized in a single message, highlight it again and pick a new size from the dropdown, or select all the text with Ctrl+A (or Cmd+A on Mac) and reset it to your default size.
Frequently Asked Questions
Does changing my font size affect emails I have already sent?
No. Changing your default font size only affects new messages you write going forward. Messages you have already sent cannot be changed. If you resize text in a draft before sending, that change applies only to that one message.
Will my recipient see the same font size I chose?
Not necessarily. The recipient's email client and display settings control how large the text appears on their screen. Your font size choice is included in the message, but their Outlook, Gmail, or other email program may override it based on their own preferences.
Can I set different default font sizes for different email accounts?
Yes. If you have multiple accounts in Outlook desktop, you can set a default font size for each account separately. Go to File > Options > Mail > Compose messages > Stationery and Fonts and look for the dropdown that lets you choose which account the settings apply to.
What if the font size dropdown is not visible in my toolbar?
In Outlook on the web, click the three dots (more options) in the compose toolbar to reveal additional formatting tools. In Outlook desktop, make sure you are in the compose window, not just reading a message. If it is still missing, the toolbar may be customized — right-click the toolbar and select an option to restore default buttons.