Image aspect ratio calculator
Calculate a simplified width-to-height ratio from any image dimensions, without uploading files.
Quick answer
An aspect ratio compares image width and height. Divide both pixel values by their greatest common divisor (GCD): 1920 × 1080 becomes 16:9, 1080 × 1920 becomes 9:16, and 1080 × 1350 becomes 4:5. It describes the image shape, not its resolution or visual quality.
Make it precise.
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Aspect ratio calculator
Turn width and height into a clean, simplified ratio.
Landscape format · 1.7778:1
Change either number and the ratio updates automatically.
Add an image to activate the download.
The quality slider affects JPEG and WebP; PNG export is lossless. Padding uses the chosen background color.
Check your image's maximum print size at a chosen resolution.
Based on image pixel dimensions; actual print results vary by printer, viewing distance and image quality.
Tip: 300 PPI is a common target for sharp close-viewed prints, not a universal requirement.
How to calculate and simplify an aspect ratio
- Enter the image width and height in pixels above.
- Read the simplified width:height ratio; the calculator updates instantly.
- Try the presets or use “Copy ratio” to reuse your result.
Formula: width ÷ GCD(width, height) : height ÷ GCD(width, height). For 1920 × 1080 pixels, the GCD is 120, so the ratio is 16:9.
Common image aspect ratios
| Pixel dimensions | Ratio | Orientation |
|---|---|---|
| 1920 × 1080 | 16:9 | Landscape widescreen |
| 1080 × 1920 | 9:16 | Vertical story / video |
| 1080 × 1350 | 4:5 | Portrait post |
| 1080 × 1080 | 1:1 | Square |
| 6000 × 4000 | 3:2 | Landscape photo |
These values are examples of image shape, not guaranteed platform upload specifications.
Questions about aspect ratios
Are 1920 × 1080 and 1280 × 720 the same aspect ratio?
Yes. Both reduce to 16:9. They have different resolutions but the same shape.
Does resizing an image change its aspect ratio?
Not when width and height are scaled proportionally. Changing dimensions by different factors will change the shape or cause distortion.
How do I switch from a landscape to a portrait ratio?
Swapping width and height converts 16:9 to 9:16. To fill a portrait frame using landscape content, cropping may be required.