Formula and method
simplified ratio = width ÷ GCD(width, height) : height ÷ GCD(width, height)
Whole-number dimensions are divided by their greatest common divisor. For decimal dimensions, the calculator also reports width ÷ height so uncommon ratios remain meaningful.
Assumptions and limits
- Manual width and height describe the same unit.
- Image files are read locally and are never uploaded.
- Fit preserves the whole image; crop fills the target and removes overflow.
Worked examples
1920 × 1080 video
The greatest common divisor is 120. Dividing both dimensions by 120 gives the familiar 16:9 ratio.
4032 × 3024 photo
Both values divide by 1008, giving 4:3. At a target width of 1600 pixels, the proportional height is 1200 pixels.
Common aspect ratios
| Ratio | Decimal | Common use |
|---|---|---|
| 1:1 | 1.000 | Square images and avatars |
| 4:3 | 1.333 | Cameras and classic displays |
| 16:9 | 1.778 | Video, TVs and monitors |
| 21:9 | 2.333 | Ultrawide displays |
Frequently asked questions
Does uploading an image send it anywhere?
No. The browser reads only its local dimensions. The file is not uploaded or stored.
What is the difference between fit and crop?
Fit keeps the complete image and may add empty space. Crop fills the target area and trims the extra width or height.