21:9 Aspect Ratio Calculator
Enter a width or height to instantly calculate the matching 21:9 (or 64:27) ultrawide dimension and see common standard resolutions for reference.
Ratio Calculator
Please enter a positive number.
Result
Enter a value and click Calculate.
21:9
Width
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Height
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Resolution
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Standard 21:9 Resolutions
| Resolution | Common Name | Ratio |
|---|---|---|
| 2560 × 1080 | UWFHD | 64:27 |
| 3440 × 1440 | UWQHD | 64:27 |
| 5120 × 2160 | 5K2K / UW5K | 64:27 |
| 2520 × 1080 | Exact 21:9 | 21:9 |
| 3360 × 1440 | Exact 21:9 QHD | 21:9 |
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Summary
Enter a width or height to instantly calculate the matching 21:9 (or 64:27) ultrawide dimension and see common standard resolutions for reference.
How it works
- Select whether you are providing the Width or Height.
- Choose the ratio variant: 21:9 (exact) or 64:27 (monitor standard).
- Enter the known pixel (or unit) value.
- The calculator instantly outputs the corresponding dimension.
- Copy either result with one click, or use the standard resolution table as a reference.
Use cases
- Size a video export canvas for an ultrawide monitor.
- Crop gameplay footage to 21:9 before uploading.
- Design UI mockups targeted at ultrawide displays.
- Verify that a custom resolution maintains the correct 21:9 ratio.
- Convert an existing 16:9 width to an equivalent 21:9 height for letterbox comparison.
- Check whether a monitor resolution is true 21:9 or the 64:27 variant.
- Scale thumbnail art to fill an ultrawide banner without distortion.
- Plan camera sensor crop factors for anamorphic lenses.
Frequently Asked Questions
Last updated: 2026-07-01 ·
Reviewed by Nham Vu