How to Change Slide Size in PowerPoint
Change PowerPoint slide size from the Design tab. Switch between 16:9 and 4:3, set custom dimensions, and pick Maximize or Ensure Fit safely.
PowerPoint keeps all slide dimensions in one place: the Design tab. Open your deck, click Design > Slide Size, and choose Widescreen (16:9), Standard (4:3), or Custom Slide Size. The change applies to every slide at once — a single deck can’t mix sizes — so it pays to set your size before you build the content.
Switch between widescreen and standard
Widescreen 16:9 has been the default since PowerPoint 2013 and measures 13.333 x 7.5 inches, matching modern monitors and TVs. Standard 4:3 (10 x 7.5 inches) suits older projectors and some printed handouts. The Slide Size button sits at the far-right end of the Design ribbon; click it and pick the ratio you need.
| Preset | Aspect ratio | Dimensions | Best for |
|---|---|---|---|
| Widescreen | 16:9 | 13.333 x 7.5 in | Modern screens, video |
| Standard | 4:3 | 10 x 7.5 in | Older projectors, handouts |
Set an exact custom size
For anything else — a poster, a square social image, or A4 paper — choose Custom Slide Size. In the dialog you can type a width and height (PowerPoint accepts up to 56 inches per side), switch orientation between portrait and landscape, or pick a ready-made format from the Slides sized for menu (A3, A4, Banner, and more). You can enter measurements in inches, centimeters, or pixels.
Keep your content from breaking
If a slide already holds content, PowerPoint asks how to rescale it. Maximize keeps items large but can push them past the edges; Ensure Fit shrinks everything so nothing gets cropped.
| Option | What it does | Use when |
|---|---|---|
| Maximize | Fills the new size, may crop | Moving to a larger slide |
| Ensure Fit | Scales down, nothing cut off | Going smaller, or unsure |
The same “set it up first” habit saves rework across Office — changing margins in Word is far easier before you pour in text, too. And once the deck looks right and you plan to send it out, you can password-protect the exported PDF before sharing.
Change the size first, then design. Resizing a finished deck almost always means nudging text boxes and images back into place, so commit to 16:9 (or your custom size) on slide one and build from there.