How to Change Font Size on Any Device or App
Font size seems like a simple setting — and often it is. But depending on where you're working and what you're trying to achieve, "changing the font size" can mean a handful of different things. This guide walks through how it works across the most common platforms and tools, and what factors shape the right approach for your situation.
What "Font Size" Actually Controls
Font size refers to the height of text characters, measured in points (pt) in most word processors and design tools, or in pixels (px) or relative units like em and rem in web contexts. One point equals 1/72 of an inch in print contexts — so a 72pt font is roughly one inch tall on paper.
In everyday apps, you don't need to think in those units. You're usually picking from a dropdown or sliding a scale. But understanding what the number means helps when you're copying settings between apps or troubleshooting text that looks unexpectedly large or small.
There are also two distinct levels where font size can live:
- Document-level or selection-level size — the size of specific text within a file (a Word doc, a slide, an email)
- System-level display size — the size of all text across your entire operating system interface
These are separate controls, and changing one won't affect the other.
How to Change Font Size in Common Apps 🖥️
Microsoft Word and Google Docs
In both apps, the process is essentially the same:
- Select the text you want to resize
- Find the font size field in the toolbar (it shows a number, usually 11 or 12 by default)
- Type a new number or click the arrows to increase/decrease
In Word, you can also use keyboard shortcuts:
Ctrl+Shift+>(Windows) orCmd+Shift+>(Mac) — increase font sizeCtrl+Shift+<(Windows) orCmd+Shift+<(Mac) — decrease font size
In Google Docs, the same shortcuts apply. You can also use Format > Text > Size.
If you're using styles (Heading 1, Body Text, etc.), changing the font size of a style updates every paragraph using that style at once — which is far more efficient than resizing text manually.
Microsoft PowerPoint and Google Slides
Same toolbar-based approach. The key difference: text in presentations lives inside text boxes, so you need to click into the text box, select the text, then adjust. Resizing the text box itself does not resize the font.
Excel and Google Sheets
Cell text size works the same way — select cells, use the font size dropdown. Keep in mind that increasing font size in a cell doesn't automatically expand the row height; you may need to adjust that separately.
Email Clients (Gmail, Outlook)
In Gmail, formatting options appear when you click the A icon in the compose toolbar. In Outlook, the font size dropdown is visible in the message ribbon. These only affect the outgoing email's body text — not the interface itself.
How to Change Font Size at the System Level
Windows
Go to Settings > Accessibility > Text size (Windows 11) or Settings > Ease of Access > Display (Windows 10). Drag the Text size slider to scale text across the entire OS interface — menus, labels, notifications.
Separately, Display scale (Settings > Display > Scale) increases or decreases the size of everything — text, icons, and UI elements together.
macOS
Navigate to System Settings > Accessibility > Display and adjust Display size or Reduce motion options. For sidebar and menu text specifically, some apps let you adjust font size within their own preferences.
Android
Go to Settings > Display > Font size and style (exact path varies by manufacturer). Most Android devices offer a slider ranging from small to large, with some offering an "Extra large" option.
iOS / iPadOS
Go to Settings > Display & Brightness > Text Size for the global text size slider. For even larger text, Settings > Accessibility > Display & Text Size > Larger Text extends the range further.
Apps that support Apple's Dynamic Type standard will automatically reflow text at any size. Apps that don't support it may not respond to this setting.
Variables That Affect Your Results 📐
Not every font size change works the same way. Here's what shapes the outcome:
| Factor | Why It Matters |
|---|---|
| App support | Some apps ignore system-level size settings |
| Font type | Some typefaces look larger or smaller at the same point size |
| Display resolution | High-DPI/Retina screens render text differently than standard displays |
| Document template | Pre-set styles can override manual changes |
| OS version | Accessibility options vary by version |
| Device type | Mobile, tablet, and desktop controls are often in different locations |
A 14pt font in one typeface can look visually equivalent to a 12pt font in another. Body text readability also varies by line spacing, contrast, and column width — font size is one piece of a larger picture.
The Difference Between Zoom and Font Size
These are frequently confused. Zoom scales everything on screen temporarily, without changing the actual font size stored in a document. Font size is a permanent property of the text itself.
If you increase zoom in a browser or Word, the document looks larger on your screen — but when someone else opens it, or when it prints, the font size is unchanged. If you want the text to actually be larger (in print, in shared files, or persistently), you need to change the font size directly. 🔠
What Shapes the Right Setting for You
A student building a presentation for a large classroom screen has different needs than someone adjusting their phone's text for low-vision accessibility. A developer working in a code editor may need to configure font size inside the editor's own settings — separate from both the OS and any documents. Someone maintaining brand consistency in a business template needs to work within defined style rules rather than ad hoc resizing.
The mechanics are consistent across platforms. What varies is which level of control actually solves your specific problem — and whether you need a one-time fix, a persistent default, or a system-wide change that follows you across every app.