Aspect Ratio Calculator
Calculate dimensions for social media, video, photography, and screens
Original Size
Enter dimensions in any unit
Target Size
Enter target width or height
What is an Aspect Ratio?
An aspect ratio describes the proportional relationship between width and height. Written as W:H (e.g., 16:9), it tells you the shape of a screen, image, or video frame. A 16:9 ratio means for every 16 units of width, the height is 9 units — the standard for HD and 4K video. A 1:1 ratio is a perfect square, used for Instagram feed posts.
Common Aspect Ratios
| Ratio | Decimal | Use Case | Where It's Used |
|---|---|---|---|
| 16:9 | 1.778 | Widescreen video & streaming | YouTube, Netflix, TV, monitors |
| 9:16 | 0.563 | Vertical video | TikTok, Instagram Reels, YouTube Shorts |
| 1:1 | 1.000 | Square posts | Instagram feed, Facebook, profile images |
| 4:5 | 0.800 | Portrait posts | Instagram portrait, social media feeds |
| 4:3 | 1.333 | Classic TV & presentations | PowerPoint, iPad, legacy broadcasts |
| 3:2 | 1.500 | Photography | DSLR cameras, 4x6 prints, 35mm film |
| 5:4 | 1.250 | Portrait prints | 8x10 prints, medium format cameras |
| 2.39:1 | 2.390 | Cinemascope / anamorphic | Theatrical films, DCI projection |
| 1.85:1 | 1.850 | Theatrical flat | Wide-release cinema, IMAX digital |
| 21:9 | 2.333 | Ultrawide monitors | Gaming, ultrawide displays |
How to Use This Calculator
Calculator: Enter your original dimensions (the ratio locks automatically), then type a new width or height — the other dimension calculates instantly. Pick a platform preset to auto-fill recommended dimensions.
Find Ratio: Enter any width and height to discover the simplified ratio, decimal value, closest standard match, and CSS padding-bottom value. Upload an image to instantly detect its dimensions.
Image Wizard: Upload any image and choose where you want to use it — social media, websites, print, or personal use. Get instant recommendations with crop analysis and one-click dimension copying.
Social Media Image Sizes (2026)
| Platform | Format | Dimensions | Ratio |
|---|---|---|---|
| Post | 1080 × 1080 | 1:1 | |
| Story / Reel | 1080 × 1920 | 9:16 | |
| Portrait | 1080 × 1350 | 4:5 | |
| YouTube | Video | 1920 × 1080 | 16:9 |
| YouTube | Shorts | 1080 × 1920 | 9:16 |
| TikTok | Video | 1080 × 1920 | 9:16 |
| X / Twitter | Post | 1600 × 900 | 16:9 |
| X / Twitter | Header | 1500 × 500 | 3:1 |
| Post | 1200 × 627 | 1.91:1 | |
| Banner | 1584 × 396 | 4:1 | |
| Post | 1200 × 630 | 1.91:1 | |
| Cover | 820 × 312 | 2.63:1 | |
| Pin | 1000 × 1500 | 2:3 |