Ultrawide Aspect Ratio Calculator
Scale using your screen’s actual ratio, or choose strict 21:9.
Locked ratio 43:18 · Actual pixel ratio
Height · exact
Whole pixels — no rounding needed.
Precision detail
- Target ratio
- 43:18
- Exact height
- 1440/1 px
- Decimal
- 1440 px
- Rounded
- 1,440 px (half up)
Parentheses mark repeating digits; … marks a truncated decimal. Fractions are exact.
Ratio stays locked to your selection. Change the known dimension to scale.
21:9 is a category, not every screen’s exact ratio
3440 × 1440 reduces to 43:18. Scaling it to 1720 pixels wide gives 720 pixels high. Strict 21:9 at 3440 wide gives approximately 1474.29 pixels high instead of 1440.
| Resolution | Exact ratio | Half-size example |
|---|---|---|
| 3440 × 1440 | 43:18 | 1720 × 720 |
| 2560 × 1080 | 64:27 | 1280 × 540 |
| 3840 × 1600 | 12:5 | 1920 × 800 |
| 5120 × 2160 | 64:27 | 2560 × 1080 |
Select a screen above, choose the side you know, then enter its new size. Selecting a different screen keeps your input and changes only the ratio. Rounded pixels may slightly change the final shape. This tool calculates dimensions; it does not change display settings or resize files.
Aspect ratio calculator — find the ratio of any other resolutionHow to calculate ultrawide aspect ratio
- 1Choose a screen. Select actual pixel dimensions or strict 21:9. The ratio stays locked.
- 2Scale. Choose the side you know and enter its new size.
- 3Copy. Copy the dimensions. Expand precision detail when the result is rounded.
This calculator returns dimensions and aspect ratios; it does not resize or crop files.
Ultrawide aspect ratio examples
- 3440 × 1440 → half size1720 × 720
- 2560 × 1080 → half size1280 × 540
- 3840 × 1600 → half size1920 × 800
- 5120 × 2160 → half size2560 × 1080
- Strict 21:9 at 3440 wide3440 × 1474 px (rounded)