Method 1: Temporarily Change Font Size While Reading (Zoom)

This is the quickest way to make an email easier to read without changing any permanent settings. This method only affects the email you are currently viewing.

1. Open an email in either the Reading Pane or in a new window.
2. Locate the Zoom slider at the very bottom-right corner of the Outlook window.
3. Drag the slider to the right to increase the font size or to the left to decrease it. A percentage indicator will show you the current zoom level. 100% is the default.
4. Alternatively, if your mouse has a scroll wheel, you can hold down the Ctrl key on your keyboard and scroll the mouse wheel up to zoom in or down to zoom out.

Method 2: Permanently Change the Default Font for New Emails

If you want all the emails you write to have a different default font size, you need to change the "Stationery" settings. This affects new messages, replies, and forwards.

1. In the main Outlook window, click on the File tab in the top-left corner.
2. From the menu on the left, select Options. This will open the Outlook Options window.
3. In the Outlook Options window, click on the Mail category from the left-hand pane.
4. Look for the "Compose messages" section and click the Stationery and Fonts... button.
5. A new "Signatures and Stationery" window will appear. Under the "Personal Stationery" tab, you will see three options you can change:
   • New mail messages: This sets the default font for brand new emails you compose.
   • Replying or forwarding messages: This sets the font when you reply to or forward an email. Many people set this to a different colour to distinguish their reply from the original text.
   • Composing and reading plain text messages: This changes the font for plain text emails, which have no formatting.
6. Click the Font... button for the option you wish to change. Select your desired font, font style, size, and colour. Click OK when you are done.
7. Repeat for the other options if needed. Click OK on the "Signatures and Stationery" window, and then OK again on the "Outlook Options" window to save everything.

Method 3: Adjust Font Size for the Inbox and Folder List

If the list of your emails (the message list) or the folder names on the left are too small, you can adjust these interface fonts. This does not change the content of the emails themselves.

1. Click on the View tab in the Outlook ribbon at the top of the window.
2. In the "Current View" group, click on View Settings.
3. In the "Advanced View Settings" dialogue box, click on Other Settings....
4. Here you can change the fonts for different parts of the view. Click the Font... button next to Column Headings to change the font for headers like "From," "Subject," and "Received."
5. Click the Font... button next to Row Font to change the font for the actual email list items (the sender and subject line of each email).
6. Choose your preferred font and size, then click OK on each window to apply the changes.

To change the font size for the Folder Pane (the list of your folders like Inbox, Sent Items, etc.), the steps are slightly different:

1. Go to File > Options > Advanced.
2. Scroll down to the "Display" section and ensure the option "Use system settings for scaling" is considered, but for direct control, the primary method is adjusting your overall Windows scaling settings. For a more direct approach within Outlook:
3. Go to the View tab > Layout > Folder Pane. While there isn't a direct font size button here, making sure it's not set to "Off" or "Minimized" is the first step. The font size in this pane is more closely tied to your overall Windows display settings. To change it, you would typically right-click your desktop, go to Display settings, and adjust the Scale percentage. This will affect all applications, not just Outlook.

Method 4: Change Font Size in Outlook on the Web (Outlook.com)

If you use Outlook through a web browser (like Edge, Chrome, or Firefox), the settings are in a different place.

To change the composing font:

1. Log in to your account at Outlook.com.
2. Click the Settings icon (a small gear) in the top-right corner of the page.
3. In the settings panel that opens, click on Mail and then select Compose and reply.
4. Scroll down to the "Message format" section. Here you can use the dropdown menus to select the default font, font size, and formatting for all new messages you write.
5. Click the Save button at the bottom once you have made your changes.

To change the reading font size (or the whole interface):

Outlook on the Web doesn't have a dedicated zoom feature like the desktop app. Instead, you use your web browser's built-in zoom function. This will resize everything on the page, not just the email text.

• Press Ctrl and + (the plus key) to zoom in.
• Press Ctrl and - (the minus key) to zoom out.
• Press Ctrl and 0 (the zero key) to reset the zoom to 100%.

Method 5: Adjust Font Size on the Outlook Mobile App (iOS and Android)

The Outlook mobile app is designed to respect the system-wide text size settings of your phone. There is no specific in-app setting to change the font size; instead, you change it for your entire device, and Outlook will adapt.

For iOS (iPhone/iPad):

1. Open the Settings app.
2. Go to Accessibility.
3. Tap on Display & Text Size.
4. Tap on Larger Text.
5. Drag the slider to adjust the text size for all apps that support Dynamic Type, including Outlook.

For Android:

1. Open the Settings app.
2. Go to Display (this may also be under Accessibility on some devices).
3. Tap on Font size and style or simply Font size.
4. Use the slider at the bottom of the screen to choose your preferred size. The changes will be reflected in the Outlook app.