Calculator Form
Example Data Table
| Resolution | Reduced Ratio | Decimal Ratio | Common Label | Typical Use |
|---|---|---|---|---|
| 1280 × 720 | 16:9 | 1.7778 | 16:9 | HD video |
| 1920 × 1080 | 16:9 | 1.7778 | 16:9 | Full HD displays |
| 1440 × 1080 | 4:3 | 1.3333 | 4:3 | Classic video frames |
| 2560 × 1440 | 16:9 | 1.7778 | 16:9 | QHD monitors |
| 3440 × 1440 | 43:18 | 2.3889 | 21:9 | Ultrawide screens |
| 1080 × 1920 | 9:16 | 0.5625 | 9:16 | Vertical content |
Formula Used
The reduced storage aspect ratio comes from dividing width and height by their greatest common divisor. That process removes extra scaling while keeping the same proportion.
Reduced ratio: width:gcd and height:gcd, where gcd is the greatest common divisor.
Decimal ratio: width ÷ height.
Display ratio with non square pixels: (width × pixel aspect ratio) ÷ height.
Scaled height from target width: target width ÷ display ratio.
Scaled width from target height: target height × display ratio.
Pixel density: √(width² + height²) ÷ diagonal inches.
How to Use This Calculator
- Enter the source width and height in pixels.
- Leave pixel aspect ratio at 1 for square pixels.
- Add one target dimension to compute the matching side.
- Add both target dimensions to compare fit and fill scaling.
- Enter diagonal size only when you want PPI.
- Choose the rounding mode that matches your workflow.
- Press the calculate button to show the result block.
- Use the CSV or PDF buttons to export the summary.
About Resolution and Aspect Ratio
Why the ratio matters
Resolution tells you how many pixels exist. Aspect ratio tells you how those pixels are shaped as a frame. Both values matter. A high resolution can still look awkward if the ratio does not match the target screen.
When to use display ratio
Most modern images use square pixels. In that case, storage ratio and display ratio are the same. Some legacy video formats use non square pixels. Then the display ratio changes because each pixel stretches horizontally or vertically.
Why fit and fill give different answers
Fit keeps the whole image visible. It leaves empty space when the target box has a different shape. Fill covers the whole box. It usually crops part of the frame. Both methods preserve the original proportion.
Where this calculator helps
This calculator helps with video editing, responsive images, presentation design, social posts, and display planning. It also helps when you must resize an asset without distortion, check a common standard, or estimate pixel density for a screen.
FAQs
1. What does aspect ratio mean?
Aspect ratio compares width to height. It describes the frame shape, not the pixel count. A 16:9 frame stays 16:9 at many different resolutions.
2. Why can the reduced ratio differ from a common label?
Some resolutions simplify to unusual ratios, then sit very close to a familiar standard. For example, 3440 × 1440 reduces to 43:18, but it is commonly treated as ultrawide 21:9.
3. What is pixel aspect ratio?
Pixel aspect ratio describes pixel shape. A value of 1 means square pixels. Values above or below 1 stretch the displayed image even when stored width and height stay the same.
4. Should I use fit or fill?
Use fit when you must keep every part visible. Use fill when the target area must be fully covered and cropping is acceptable.
5. Does changing resolution change aspect ratio?
Not always. If width and height scale by the same factor, the ratio stays unchanged. If only one side changes, the frame shape changes too.
6. Can this calculator help with social media sizes?
Yes. Enter the original resolution, then add a target width, height, or both. The result helps you prepare resized assets for stories, posts, banners, or thumbnails.
7. What is PPI in this calculator?
PPI means pixels per inch. It estimates display sharpness by comparing pixel diagonal length with physical screen diagonal size.
8. Why do exported values matter?
Exports make it easier to share decisions with clients, editors, or teammates. You can keep a record of resizing targets, ratios, and density checks for later work.