Change font size in Outlook through the formatting toolbar or settings
The fastest way to change font size in Outlook is using the font size dropdown in the toolbar while you're composing an email. Open a new message, select the text you want to resize, click the font size box (it shows a number like "11"), and pick a larger or smaller size from the list. If you want to set a default font size for all your emails going forward, you can change that in Outlook's settings so you don't have to adjust it every time.
The exact steps depend on whether you're using Outlook on Windows, Mac, or the web version, but the principle is the same in all three: find the formatting toolbar, locate the font size control, and either change the current message or adjust your default settings.
Key Takeaways
- The font size dropdown appears in the toolbar while composing an email and lets you resize selected text immediately.
- On Windows Outlook, the font size box is in the Home tab of the ribbon; on Mac, it's in the Message tab.
- You can set a permanent default font size in Outlook settings so new emails always start at your preferred size.
- Outlook on the web uses a slightly different toolbar layout but has the same font size control in the formatting options.
Changing font size in a single email on Windows
Open Outlook and create a new email by clicking "New Email" or pressing Ctrl+N. Start typing your message or paste text you want to resize. Highlight the text by clicking and dragging across it, or triple-click to select an entire paragraph.
Look at the top of the compose window for the ribbon menu. Click the "Home" tab if it's not already selected. In the toolbar, find the font size box — it's a small dropdown showing a number (usually "11" by default). Click the dropdown arrow next to it and select a new size from the list. Common sizes range from 8 to 28 points. The text you selected will resize immediately.
If you don't see the font size box, your ribbon may be minimized. Click the up arrow at the far right of the ribbon to expand it fully.
Changing font size in a single email on Mac
Create a new email in Outlook for Mac by pressing Command+N or clicking "New Email." Type or paste your message, then highlight the text you want to resize by clicking and dragging across it.
Click the "Message" tab in the ribbon at the top. Look for the font size control in the formatting section — it's labeled with a number and a small dropdown arrow. Click the dropdown and choose your preferred size. The change takes effect immediately on the selected text.
If the Message tab doesn't show formatting options, make sure the ribbon is expanded by clicking the expand icon at the top right of the window.
Changing font size in Outlook on the web
Log into your Outlook account at outlook.com or outlook.office.com. Click "New Message" to start composing an email. Type your message or paste text, then select the text you want to resize.
Look for the formatting toolbar above the compose area. Click the font size dropdown — it typically shows a number like "14" or "16" by default. Select a new size from the menu. The text resizes instantly. If you don't see the formatting toolbar, click the three-dot menu icon and look for text formatting options.
Setting a default font size for all new emails
On Windows: Open Outlook and go to File > Options > Mail > Stationery and Fonts. Under "Composing messages," click "Fonts." Select your preferred font size in the "Font size" field, then click OK. This size will now be the default for all new emails you compose.
On Mac: Open Outlook and click Outlook > Preferences > Composing. Find the font size setting and change it to your preference. Click the red close button to save and return to Outlook.
On Outlook on the web: Click the gear icon in the top right corner and select "View all Outlook settings." Go to Mail > Compose and reply. Look for the default font size option and change it. Your preference saves automatically.
Changing font size for received emails you're reading
If you want to make received emails easier to read by enlarging the text, you can zoom in on the message without changing the original email. Open any email and use Ctrl+Plus (Windows) or Command+Plus (Mac) to zoom in. Use Ctrl+Minus or Command+Minus to zoom back out. This zoom applies only to what you're viewing and doesn't change how the email appears to others.
Alternatively, you can change the default reading font size in Outlook settings. On Windows, go to File > Options > Mail > Stationery and Fonts and adjust the font size under "Reading messages." On Mac, go to Outlook > Preferences > Viewing and adjust the font size there.
Troubleshooting font size changes that don't stick
If you set a default font size but new emails still open in a different size, check that you saved your changes. In Windows, make sure you clicked OK after changing the font size in Stationery and Fonts. On Mac, close the Preferences window completely so your changes register.
If you're using Outlook on the web and changes aren't saving, try clearing your browser cache and logging back in. Sometimes cached settings override new preferences. If the problem persists, try a different browser to rule out a browser-specific issue.
Frequently Asked Questions
Can I change font size for just one paragraph in an email?
Yes. Select only the paragraph you want to resize by clicking and dragging across it, then use the font size dropdown. Other text in the email stays at its original size. You can resize different parts of the same email to different sizes.
What's the largest font size Outlook offers?
The default dropdown goes up to 28 points, but you can type a larger number directly into the font size box if you need it. Click the box, clear the current number, type a custom size, and press Enter.
Does changing my default font size affect emails I've already sent?
No. Changing your default font size only affects new emails you compose going forward. Emails already sent or received are not affected by changes to your settings.
Why does my font size look different on the recipient's screen?
Recipients may have their own zoom settings or default font preferences that override what you send. Some email clients also render fonts differently. The size you set is what you're sending, but how it displays depends partly on their device and email program.
Can I make font size changes stick across all my devices?
If you use Outlook on the web, your settings sync across devices automatically. If you use Outlook desktop on multiple computers, you need to change the default font size on each device separately, as those settings don't sync between installations.