Step 1: Start a New Presentation:
- Open Google Slides.
- Click the "+ New" button or directly open a blank slide.

Step 2: Adjust Slide Dimensions:
- After opening a new presentation, locate the "File" option in the top left corner.
- From the drop-down menu, choose "Page setup."

Step 3: Customize Page Size:
- In the "Page setup" window, find the "Slides" section.
- Select "Custom" beside "Size" for slides with non-standard dimensions.
- Enter your preferred width and height for portrait slides. For instance, you can input 8.5 inches for width and 11 inches for height to achieve the US Letter portrait size.

Step 4: Apply Changes:
- Once you've entered the dimensions, click "Apply."
- A confirmation message will appear, stating that the change is specific to this presentation. Confirm by clicking "OK."

Share on socials
About the author
Sanskar Tiwari is the founder of MagicSlides and IAG Tech. Over the past 5 years, he has shipped 24+ products and taught 100k+ students how to code. His work focuses on AI‑assisted creation and developer education.
More from the blog
Best Fonts for PPT: Top PowerPoint Fonts for Readability & Engagement
7 April 2026
How to Improve Slide Design for Presentations?
6 April 2026
How to Use Google Form Autofill Bot? Step-By-Step Guide
6 April 2026
How to Download Presentation from Gamma App: Easy Ways to Export, Convert & Save Slides
5 April 2026
How to Check Word Count in Google Docs: A Complete Guide
5 April 2026
How to Insert Bitmoji into Google Slides? Complete Guide
3 April 2026
How to Create a Timeline Slide for Presentation with AI
3 April 2026
How to Delete a Photo on Google Slides (6 Simple Ways).
3 April 2026
How to Add Subscript to Text in Google Slides? Explained
3 April 2026