Ultrawide calculator
21:9 Aspect Ratio Calculator
Use this 21:9 calculator for wide cinematic images, ultrawide screenshots, and immersive desktop layouts.
Ratio preview
Ultrawide format
Ultrawide monitors, cinematic hero sections, banners, landing page media, and wide presentation visuals.
Calculate 21:9 dimensions
Enter width or height. The matching dimension updates automatically to keep the 21:9 shape.
21:9 result
2,560 × 1,097
21:9 ratio
- Decimal
- 2.333:1
- Orientation
- Landscape
- CSS
- aspect-ratio: 21 / 9;
Common 21:9 sizes
| Use | Size | Note |
|---|---|---|
| Ultrawide monitor | 2560 × 1080 | Common ultrawide display resolution, close to 21:9. |
| Cinematic export | 2520 × 1080 | Exact 21:9 dimensions from 1080 height. |
| Large banner | 3360 × 1440 | Common high-resolution ultrawide display size. |
| Web hero | 2100 × 900 | Simple exact 21:9 website banner. |
Best uses
Direct answer
What is the 21:9 aspect ratio?
Calculate 21:9 ultrawide dimensions for cinematic banners, ultrawide monitor screenshots, and hero layouts.
Find height
height = width × 9 ÷ 21
Find width
width = height × 21 ÷ 9
| Concept | What it describes | Example |
|---|---|---|
| Aspect ratio | The proportional shape of a frame | 21:9 |
| Resolution | The number of pixels in that frame | 2560 × 1080 |
Crop and placement check
Check the destination frame before export. Cropping fills the placement; padding or letterboxing preserves the complete source.
How to use 21:9
Use 21:9 for cinematic wide layouts
Use 21:9 when you need a cinematic banner, ultrawide monitor screenshot, or immersive website hero. Keep critical text away from the far left and right because responsive layouts may crop wide edges.
Frequently asked questions
Is 2560 × 1080 exactly 21:9?
It is commonly called 21:9, but mathematically it is slightly wider than exact 21:9. The calculator can produce exact matching dimensions.
When should I use 21:9?
Use it for cinematic banners, ultrawide monitor visuals, and desktop hero layouts.
Will 21:9 crop on mobile?
Often yes. Keep important subjects centered and create separate mobile crops when needed.
Is 21:9 the same as 2560 × 1080?
2560 × 1080 is commonly treated as ultrawide, but exact 21:9 from 1080 height is 2520 × 1080. Use the calculator when exact matching matters.
More ratio calculators
Continue with another ratio
Use dedicated pages when you know the final placement or content shape.
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Related guides
Use these supporting guides to understand the tool result and next testing steps.
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