How to Change the Font Size in Outlook (Every Method Explained)

Microsoft Outlook gives you more control over font size than most people realize — but the settings aren't all in one place. Depending on what you're trying to resize and which version of Outlook you're using, the steps differ significantly. Here's a clear breakdown of every approach.

What You're Actually Changing (And Why It Matters)

Before diving into steps, it helps to separate the two different things people mean when they ask about font size in Outlook:

1. Message composition font size — the default size of text when you write a new email
2. Reading pane and interface font size — how large text appears when you're reading emails or navigating the app

These are controlled by completely different settings. Changing one won't affect the other, which is a common source of confusion.

How to Change the Default Font Size for Composing Emails

This setting controls what size your text appears at every time you start a new message.

In Outlook for Windows (Classic/Desktop)

1. Go to File → Options → Mail
2. Under the Compose messages section, click Stationery and Fonts
3. In the Personal Stationery tab, click Font under "New mail messages"
4. Choose your preferred font size from the size list
5. Click OK through all dialogs to save

You can also set a separate size for replies and forwarded messages — a useful distinction if you want your replies to appear slightly smaller than original messages to visually distinguish them in a thread.

In Outlook on the Web (OWA)

The web version handles this differently. Rather than a global default, you adjust font size per message using the formatting toolbar that appears in the compose window. There's no persistent default font size setting in the web app — each new message starts at a standard size unless you manually change it.

In the New Outlook for Windows

Microsoft's newer Outlook interface (rolling out to replace the classic desktop app) more closely mirrors the web experience. Default font customization options are more limited compared to classic Outlook, and some legacy stationery options have been removed or relocated.

How to Change Font Size While Writing a Specific Email

If you only want to resize text in a single message — not change the default — you have a few quick options:

• Highlight the text, then use the font size dropdown in the formatting toolbar
• Use the keyboard shortcut Ctrl + Shift + P (Windows) to open the font dialog
• Select text and press Ctrl + ] to increase size or Ctrl + [ to decrease it, one point at a time 🖱️

These changes apply only to that message and don't affect any defaults.

How to Change the Font Size for Reading Emails

This is about making received emails easier to read — especially useful on high-resolution displays where text can appear very small.

Zoom in on a Single Message

• At the bottom-right corner of the reading pane, there's a zoom slider you can drag
• Alternatively, hold Ctrl and scroll your mouse wheel to zoom in or out on the current message

This is temporary — it resets when you open a new message.

Change the Display Scale System-Wide

For a persistent change to how everything looks in Outlook (and across Windows), adjust your display scaling:

• Go to Windows Settings → Display → Scale and Layout
• Increase the scale percentage (e.g., from 100% to 125% or 150%)

This affects all apps, not just Outlook, so it's a trade-off worth considering.

Accessibility Settings in Outlook

In File → Options → Ease of Access (classic Outlook), you can find options that affect how the interface renders, though dedicated per-app text scaling for the reading pane is limited compared to what's available at the OS level.

Key Variables That Affect Your Options

Outlook on Mac — A Different Path

On Outlook for macOS, the default font is set through:

Outlook → Preferences → Fonts

From there you can set the default size for composing new messages, replies, and plain text messages separately. The interface looks nothing like the Windows version, so users switching between platforms often get confused looking for settings that simply aren't in the same place. ✉️

Plain Text vs. HTML — Why It Affects Your Choices

If you or your organization uses plain text email (no formatting), your font size options shrink considerably. Plain text emails don't support rich formatting, so size changes in the compose window won't carry through in plain text mode. You'd need to switch the message format to HTML or Rich Text to apply custom font sizes that recipients actually see.

What Determines the Right Font Size for You

Several personal factors shape which setting actually solves your problem:

• Your monitor size and resolution — a 4K display at 27 inches reads very differently than a 13-inch 1080p laptop
• Whether you're setting defaults or adjusting per-message — the steps are entirely different
• Which Outlook version you're running — classic desktop, new Outlook, web app, or mobile each have separate controls
• Whether you want changes for composing, reading, or both — these require separate adjustments
• How much control you want — OS-level scaling is blunt but consistent; app-level settings are precise but limited in scope

The right combination of settings depends entirely on your screen setup, how you use email day-to-day, and which version of Outlook your workplace or device has installed. 🖥️