No Ticket Needed

Appearance

3 min fix 10 min read Recently reviewedBeginner

By , IT support technician

Quick Answer

Click Design > Slide Size at the right-hand end of the ribbon and choose Widescreen (16:9) or Standard (4:3). For anything else, choose Custom Slide Size and enter the width and height you need.

How to Change Slide Size in PowerPoint ​

Applies to: PowerPoint for Windows and Mac (Microsoft 365, PowerPoint 2021, PowerPoint 2019), PowerPoint for the web
Article Type: How-To
Last Updated: 2026-07-29

Summary ​

Slide size is one setting that governs the whole deck, and changing it after you have built forty slides rearranges every one of them. This article shows you how to switch between 16:9 and 4:3, set custom dimensions for A4 handouts and posters, choose correctly between Maximize and Ensure Fit, and repair content that shifted during a conversion.

Prerequisites ​

  • PowerPoint desktop or PowerPoint for the web. Custom dimensions require the desktop app.
  • Edit permission on the presentation. A file opened from an email attachment may open in Protected View — click Enable Editing in the yellow banner first.
  • No admin rights required.

Instructions ​

1. Switch Between Widescreen and Standard ​

This is the change most people need, and it takes two clicks.

  1. Open the presentation and click the Design tab on the ribbon.
  2. At the far right of the ribbon, in the Customize group, click Slide Size.
  3. Choose one of the two presets in the menu:
    • Standard (4:3) — a squarer slide, 10 by 7.5 inches.
    • Widescreen (16:9) — the default since PowerPoint 2013, 13.333 by 7.5 inches.
  4. If the deck already contains content, a prompt appears asking whether to Maximize or Ensure Fit. Section 4 below explains which to pick. If the deck is empty, the change applies with no prompt.

Verification: The slide in the editing area visibly changes shape, and every slide thumbnail in the panel on the left changes with it. Slide size is a presentation-wide setting — a single deck cannot mix ratios.

2. Pick the Right Ratio for Where You Are Presenting ​

The right answer is the shape of the screen your audience looks at, not the shape of your laptop.

Choose Widescreen (16:9) when:

  • You are presenting over Microsoft Teams or Zoom. The shared-content area is wide, so a 4:3 deck appears with thick grey bars down both sides and your text renders smaller for everyone watching.
  • The room has a flat-panel TV or a modern laser projector. Nearly all hardware sold in the last decade is 16:9.
  • The deck will be read on laptops and phones rather than projected. Every current laptop screen is 16:9 or wider.
  • You are not sure. 16:9 is the safe default and the PowerPoint default.

Choose Standard (4:3) when:

  • The venue has an older ceiling projector or a square pull-down screen. A 16:9 deck on 4:3 hardware is letterboxed, and the bottom line of every slide often falls below the visible area.
  • You are printing to standard paper and want less wasted margin.
  • The organiser has told you the house template is 4:3. Some conference systems still require it.

Tip: If you are presenting remotely, run a quick check by sharing the deck in a test meeting and looking at how much of the window it fills. See How to Present in Microsoft Teams Using PowerPoint Live for the sharing method that keeps your slides sharpest.

3. Set a Custom Size for A4, Print, or Posters ​

Use the full dialog when you need exact dimensions — a printed handout, a conference poster, or a signage board.

  1. Click Design > Slide Size > Custom Slide Size. On Mac the command reads Page Setup.
  2. The Slide Size dialog opens. Use the Slides sized for dropdown at the top to pick a named preset:
    • A4 Paper (210x297 mm) — for handouts printed on A4 in most of the world.
    • Letter Paper (8.5x11 in) — the North American equivalent.
    • A3 Paper (297x420 mm) — a common small-poster size.
    • On-screen Show (16:9) or On-screen Show (4:3) — the two screen presets.
    • Custom — selected automatically as soon as you type your own dimensions.
  3. To enter your own size, type values into the Width and Height boxes. Units follow your Windows regional settings — inches or centimetres. PowerPoint accepts up to 56 inches, or 142.24 cm, on each edge.
  4. Under Orientation, set Slides to Portrait or Landscape. A portrait slide is what you want for a roll-up banner or a printed page. The separate Notes, Handouts & Outline setting below it controls printed handouts and is independent of the slides themselves.
  5. Set Number slides from if the deck is a section of a larger document and needs to start at a number other than 1.
  6. Click OK, then answer the Maximize or Ensure Fit prompt if it appears.

Note: For a poster larger than 56 inches, design at half your final dimensions and tell the print shop to output at 200%. Text and vector shapes scale without loss. Confirm any photographs are high resolution before you do this — a 72 dpi image doubled in size prints soft.

4. Choose Maximize or Ensure Fit ​

This prompt appears whenever you change the size of a deck that already has content, and most people click a button without knowing what it does. Here is what each one means.

The dialog reads: You are scaling to a new slide size. Would you like to maximize the size of your content or scale it down to ensure it will fit on the new slide?

  • Maximize scales your content up so it fills the new slide edge to edge. Nothing is left empty — but anything that no longer fits is pushed beyond the slide boundary, where it stops appearing in the slideshow. Going from 4:3 to 16:9, that means the top and bottom of tall content gets cut.
  • Ensure Fit scales your content down until everything fits inside the new slide. Nothing is lost. You get empty bands instead — at the left and right when going 4:3 to 16:9, at the top and bottom when going 16:9 to 4:3.

Pick Ensure Fit in almost every case. Empty space is a five-minute layout fix; content that has silently slid off the edge of forty slides is not, because you will not notice until you present.

Pick Maximize only when the deck is mostly full-bleed photographs and you would rather lose a few pixels from the edge of an image than see white bars.

Tip: Whichever you choose, press Ctrl + Z immediately if the result looks wrong. A single undo reverts both the size change and the scaling in one go, as long as you have not made other edits since.

5. Fix Content That Stretched or Got Cropped ​

A conversion moves things. Work through the deck in this order and it takes minutes rather than an afternoon.

  1. Find content that has fallen off the slide. Click View > Outline View to confirm all your text is still present, then return to Normal view. In the editing area, objects sitting outside the white slide rectangle are on the pasteboard and will not appear in the slideshow — drag each one back inside.
  2. Reset placeholders back to the layout. Select a slide, then click Home > Reset in the Slides group. Any title or body placeholder returns to the position and size defined by the layout. This does not affect text boxes, images, or shapes you added yourself.
  3. Repair distorted images. Click a picture that looks stretched, then click the Picture Format tab and open the Crop dropdown. Choose Fill to restore the correct proportions by trimming the overflow, or Fit to restore them by shrinking the image inside its frame.
  4. Fix the background and repeating elements once, at the master. Click View > Slide Master. Correct the logo position, footer, and title placement on the top slide in the left panel — the master — and every layout beneath it inherits the fix. Click Close Master View when you are done.
  5. Re-check tables and charts. These do not scale their internal text with the object. Select a table, click the Layout tab under Table Tools, and use Distribute Rows and Distribute Columns to even them out.

Verification: Press F5 to run the slideshow from the beginning and page through every slide. Anything cut off at an edge or overlapping is visible immediately in full-screen view but often invisible in the editing area.

6. Set the Size Before You Build the Deck ​

The cleanest conversion is the one you never run. Make the size decision your first action on a new presentation.

  1. Create the new presentation, before adding any slides beyond the title.
  2. Click Design > Slide Size and set the ratio or custom dimensions you need. With an empty deck there is no Maximize or Ensure Fit prompt, because there is nothing to scale.
  3. Apply your theme or company template, then click View > Slide Master and confirm the placeholders sit where you want them at this size.
  4. Save the file as a template so the next deck starts correctly: click File > Save As, then choose PowerPoint Template (*.potx) in the file type dropdown.
  5. Build your content.

Note: If you have been handed a house template that is the wrong ratio, convert it once, fix the master, and save that as your own template. Converting a template is a single job; converting every deck built from it is a recurring one.

Troubleshooting ​

WARNING

Changing slide size affects the entire presentation. PowerPoint cannot mix 16:9 and 4:3 slides in one file. If you need both ratios, build two decks and link them, or export one to PDF and insert the pages as images.

Symptom / ErrorPotential CauseSolution
Text and images are cut off at the slide edgeMaximize was chosen during conversionPress Ctrl + Z to undo if you have made no other edits. Otherwise, convert back and forth choosing Ensure Fit, or drag the off-slide objects back in and use Home > Reset on affected slides.
Empty grey bars appear either side when presentingDeck ratio does not match the displayThe deck is 4:3 on a 16:9 screen. Convert to Widescreen (16:9) with Ensure Fit, then redistribute content into the new width.
Custom Slide Size is missing from the menuUsing PowerPoint for the webThe web app offers only the two presets. Click Editing > Open in Desktop App to set a custom size, then continue in the browser.
Logo and footer moved on every slideMaster layout scaled with the deckClick View > Slide Master, reposition the elements on the top master slide, and click Close Master View. Every slide updates at once.
Width or height value is rejectedValue exceeds the 56 inch limitPowerPoint caps each dimension at 56 inches, or 142.24 cm. Design the poster at half size and ask the print shop to scale the output to 200%.
Slide size reverts when reopening the fileDeck was reopened from a templateConfirm you saved the .pptx file itself rather than reopening the source .potx template. Check the file name in the title bar.