What is an Aspect Ratio?
An aspect ratio is the proportional relationship between the width and height of an image, video, or display. Expressed as two numbers separated by a colon (such as 16:9 or 4:3), it describes shape — not size. The same aspect ratio can apply to a thumbnail and a cinema screen simultaneously.
How to Calculate an Aspect Ratio
- Enter the width and height of your image or video in the "Find the Ratio" section.
- Click Calculate Ratio to see the simplified ratio, decimal, and percentage.
- To find a missing dimension instead, enter a known ratio plus one dimension, leave the other blank, and click Calculate Dimension.
Aspect Ratios for Social Media Platforms
| Platform | Recommended Ratio | Size in px |
|---|---|---|
| Instagram post | 1:1 or 4:5 | 1080x1080 or 1080x1350 |
| Instagram story | 9:16 | 1080x1920 |
| YouTube thumbnail | 16:9 | 1280x720 |
| Facebook post image | 1.91:1 | 1200x628 |
| LinkedIn banner | 4:1 | 1584x396 |
| Twitter header | 3:1 | 1500x500 |
Frequently Asked Questions
What aspect ratio is 1920x1080?
1920x1080 simplifies to a 16:9 aspect ratio. This is the standard widescreen format used for HD video, most monitors, and YouTube uploads.
What is the best aspect ratio for Instagram?
For feed posts, 1:1 (square) or 4:5 (portrait) get the most screen real estate. For Stories and Reels, use 9:16 (vertical). For carousels, 1:1 is safest for consistent cropping.
What aspect ratio should I use for print?
Standard print formats use 4:3 (6x4 inch photo), 3:2 (classic photo ratio), or A4 paper (roughly 1:√2 ≈ 1:1.414). Always confirm with your print provider before exporting final files.
Why does my image look stretched after resizing?
Stretching occurs when width and height are resized independently without maintaining the aspect ratio. Use this calculator to find the correct paired dimension before resizing.