Change font size before you write

The fastest way to change font size in Outlook is to set it before you start typing. Open a new email, then look at the toolbar above the message body. You will see a box with a number in it — usually "11" or "12" — next to a dropdown arrow. Click the arrow, select the size you want, and start typing. Everything you write will use that size until you change it again.

This method works the same way in Outlook on Windows, Outlook on Mac, and Outlook on the web. The toolbar location is slightly different on each version, but the font size dropdown is always visible and works the same way.

Key Takeaways

  • Set font size before typing by clicking the font size dropdown in the toolbar and selecting your preferred size.
  • Change font size mid-email by selecting the text you want to resize, then picking a new size from the dropdown.
  • Outlook on the web has the font size dropdown in the formatting toolbar above the message body.
  • You can also use keyboard shortcuts: Ctrl+] to increase size and Ctrl+[ to decrease size on Windows, or Cmd+] and Cmd+[ on Mac.
  • Set a default font size in Outlook settings so new emails always start with your preferred size instead of the program default.

Change font size in text you have already written

If you have already typed your message and want to change the size of some or all of it, select the text first. Click and drag to highlight the words you want to resize, or use Ctrl+A (Windows) or Cmd+A (Mac) to select everything in the message.

Once the text is highlighted, click the font size dropdown in the toolbar and choose a new size. The selected text will change when ready. You can do this as many times as you want in a single email — some text can be 12 point, other text 14 point, all in the same message.

Use keyboard shortcuts to resize faster

If you use Outlook on Windows or Mac, keyboard shortcuts let you change font size without touching the toolbar. Select the text you want to resize, then press Ctrl+] (right bracket) to make it larger or Ctrl+[ (left bracket) to make it smaller. On Mac, use Cmd+] and Cmd+[. Each time you press the shortcut, the size increases or decreases by one step.

This method is faster than clicking the dropdown if you are resizing text repeatedly. It also works if your toolbar is hidden or if you prefer to keep your hands on the keyboard.

Set a default font size so every new email starts the same way

If you always want your emails to start at a certain size — say 14 point instead of the Outlook default — you can change the default in your settings. On Windows, go to File, then Options, then Mail. Look for "Compose messages" and click the Stationery and Fonts button. Select the font size you want under "New mail messages" and click OK.

On Mac, open Outlook, go to Preferences, then Email Format. Under "Compose in this format", choose HTML, then click Fonts. Set your preferred size for new messages and click OK. On Outlook on the web, go to Settings (the gear icon), then View all Outlook settings, then Mail, then Compose and reply. Look for "Default font" and "Default font size" and change them there.

Once you set a default, every new email you create will start with that size. You can still change individual emails or sections of text at any time — the default only affects new messages you have not yet started typing.

Why font size matters in email

Larger font sizes are easier to read on phones and tablets, especially for people with vision difficulties. Smaller sizes let you fit more text on screen without scrolling. The size you choose affects how your message looks to the person reading it — if you send 10-point text to someone on a phone, they may have trouble reading it, even if it looks fine on your computer screen.

Keep in mind that the recipient's email program might override your font size. Some email clients ignore font size settings and use their own defaults instead. If readability is important, use a size between 11 and 14 point, which most programs respect and most people find straightforward to read.

Troubleshooting font size problems

If you change the font size but it does not seem to work, check whether you are composing in HTML or plain text. Outlook on the web and Outlook on Windows default to HTML, which supports font sizes. Plain text email does not — if your message is set to plain text, font size options will be grayed out or missing. To switch to HTML, look for a "Format" button in the toolbar and select HTML.

If the font size dropdown is missing from your toolbar entirely, your toolbar may be customized or hidden. On Windows, right-click the toolbar and select "Customize the Ribbon" to add the font size control back. On Mac, look for a formatting toolbar button (usually marked with an "A") and click it to show the full formatting options. On Outlook on the web, the font size dropdown should always be visible in the main toolbar above the message body.

Frequently Asked Questions

Can I make different paragraphs different sizes in the same email?

Yes. Select each paragraph or section separately and change its size. You can have one paragraph at 12 point, another at 14 point, and another at 10 point all in the same message. This is useful if you want to emphasize certain parts or make a signature smaller than the main text.

What is the largest font size Outlook supports?

Outlook supports sizes up to 72 point, though most people use sizes between 10 and 18 point for regular email. Sizes larger than 18 point are usually reserved for headings or special emphasis. The exact maximum may vary slightly depending on which version of Outlook you use.

Does the recipient see the same font size I set?

Usually yes, but not always. If you send HTML email, the recipient's program should respect your font size. If you send plain text, font size is stripped out and the recipient sees whatever their email program defaults to. Some email clients also override font sizes for accessibility reasons.

How do I make the font size bigger in emails I am reading, not writing?

That is a separate setting from compose font size. In Outlook on Windows, go to File, Options, Mail, and look for "Reading pane" settings. On Mac, go to Preferences and Mail. On Outlook on the web, go to Settings and look for "Reading pane" or "Message preview" options. You can usually zoom the entire message view using Ctrl+scroll wheel (Windows) or Cmd+scroll wheel (Mac).

Will changing my default font size affect emails I have already sent?

No. Changing your default only affects new emails you create from that point forward. Emails you have already sent cannot be changed, and emails you received are not affected. The default setting only controls what size new blank messages start with.