Aspect Ratio Calculator
Find the exact ratio of any width and height. Resize pixel dimensions without stretching, then compare physical screen shapes.
Resize dimensions
1,280 × 720 px
Simplified aspect ratio: 16:9
Shape preview
Compare physical screen shapes
Your ratio and 16:9 at the same diagonal. Panel dimensions only; bezels and stands are excluded.
- Your ratio · 16:9
- 59.77 × 33.62 cm
- 16:9 reference
- 59.77 × 33.62 cm
Common resolution examples
| Resolution | Aspect ratio |
|---|---|
| 16:9 | |
| 9:16 | |
| 16:9 | |
| 16:9 | |
| 64:27 | |
| 43:18 |
Continue with another screen tool
How to calculate and resize an aspect ratio
Enter the original width and height in the same unit. The calculator reduces them to the smallest whole-number ratio: 1920 × 1080 becomes 16:9. Enter a new width of 1280 and the matching height is 720 pixels. You can edit the new height instead; the width updates automatically.
The formula and pixel rounding
New height = new width × original height ÷ original width. New width = new height × original width ÷ original height. Ratio reduction uses the greatest common divisor. Inputs accept up to four decimal places; pixel results round to whole numbers. When rounding changes the result, the unrounded dimensions are shown too. This calculates dimensions; it does not upload or resize an image file.
Pixel dimensions and physical screen size
A ratio describes shape, not size or sharpness. 1920 × 1080 and 3840 × 2160 are both 16:9, but have different pixel counts. The screen overlay uses the diagonal you supply and assumes square pixels and a flat rectangular panel. At the same diagonal, changing the ratio changes the physical width and height. It does not measure your current screen.
FAQ
Is 3440 × 1440 exactly 21:9?
No. Dividing both dimensions by 80 gives 43:18, about 2.3889:1. Exact 21:9 reduces to 7:3, about 2.3333:1. Use the exact resolution when you need accurate resizing.
Can I use centimeters or inches?
Yes for finding a ratio, provided both original dimensions use the same unit. The resizing output is intended for pixels and rounds to whole pixels. Use the separate diagonal field for physical panel dimensions.