Glossary
What is the aspect ratio of a slide?
Aspect ratio: The aspect ratio of a slide is the proportion of its width to its height, written as width:height. The standard for presentations today is 16:9 (widescreen), while older decks and some projectors use 4:3.
The aspect ratio of a slide is the proportion of its width to its height, written as width:height. A 16:9 slide is 16 units wide for every 9 units high, whatever size it is shown at. Today 16:9, called widescreen, is the standard for presentations. Older decks and some projectors use 4:3.
The common ratios
| Ratio | Typical pixels | Size in PowerPoint | Typical use |
|---|---|---|---|
| 16:9 | 1280 × 720 or 1920 × 1080 | 13.333 × 7.5 in (33.867 × 19.05 cm) | Default in current PowerPoint, screens, video calls |
| 4:3 | 1024 × 768 | 10 × 7.5 in (25.4 × 19.05 cm) | Older decks, some projectors |
A third ratio, 16:10, appears on some laptop screens and projectors. At the same width, a 4:3 slide is a third taller than a 16:9 slide, which is why content does not carry over without changes.
How to choose and use it
- Take 16:9 unless something forces 4:3. It fits most screens and video calls. Ask whether the room has a 4:3 screen, because a 16:9 slide then shows black bars above and below.
- Decide before you build. In PowerPoint, change it under Design, Slide Size. PowerPoint asks whether to maximize the content or ensure it fits, and afterwards you must check every slide.
- Crop pictures, do not stretch them. A picture in the slide's own ratio fills it without cropping, and a stretched logo looks wrong at once.
- Keep one ratio per deck. Slides pasted from a deck with another ratio shift or scale.
Typical mistakes
- Changing the ratio at the end. Text overflows, pictures distort and the layout needs rework.
- Stretching a picture to fill the slide. Crop it instead.
- Designing for 16:9 and presenting on 4:3. The slide shrinks and text becomes small.
- Mixing ratios in one deck. The slides jump in size when you move between them.
Related terms
The ratio sets the frame. The slide layout decides what goes in it, and white space decides how much room is left. Your template's ratio is set in the slide master. To check whether text will be readable at the back of the room, use the font size calculator.
FAQ
Frequently asked questions
What is the best aspect ratio for a presentation?
16:9 in almost every case today. It matches most screens, video calls and projectors, and it is the default in current PowerPoint. Use 4:3 only if the room's equipment or an existing template requires it.
What size is a 16:9 slide in PowerPoint?
13.333 by 7.5 inches, which is 33.867 by 19.05 cm. A 4:3 slide measures 10 by 7.5 inches, or 25.4 by 19.05 cm.
How do I change the aspect ratio in PowerPoint?
Open the Design tab, choose Slide Size and pick Standard (4:3), Widescreen (16:9) or Custom Slide Size. PowerPoint asks whether to maximize the content or ensure it fits. Check every slide afterwards, because pictures and text can shift.
What happens if a 16:9 slide is shown on a 4:3 screen?
It appears with black bars above and below, so it fills the width but not the height, and everything looks smaller than intended. Check the room's screen before you present.
Keep reading
Slide design basics
- GuideBest fonts for presentations
Which fonts work for presentations, how many to use, what size to set and how to stop fonts changing when a PowerPoint file opens on another computer.
- Free toolSlide contrast checker
Check the WCAG 2.2 contrast ratio of two slide colors. See AA and AAA results for text and charts, a live slide preview and the nearest colors that pass.
- GlossaryBullet point
A bullet point is a short list item marked by a symbol. Learn when bullets work on slides, how to write them in parallel form and when a chart or table wins.
- GuidePresentation rules
What the 10-20-30, 5-5-5 and 7-7-7 rules say, where each one helps, where it misleads and which are worth following in a work deck.
- GlossaryVisual hierarchy
Visual hierarchy is the arrangement of elements so the eye reads them in order of importance. Definition, the five signals and how to apply them on slides.
Where to go next
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