Image Aspect Ratio Calculator
Read an image aspect ratio and calculate matching dimensions for 16:9, 4:3, 1:1, 4:5 and custom ratios.
Up to 20 MiB and 40 million pixels per image. Contact sheets accept 2–50 images, up to 100 MiB total. Icon outputs fit the complete image inside a square with transparent padding.
Why this tool exists
Calculate the target ratio before resizing to avoid stretching.
- ✓ automatic ratio
- ✓ common presets
- ✓ dimension calculator
- ✓ orientation
Useful for
- • social media crops
- • video thumbnails
- • web banners
Get the image shape right before you resize it
Aspect ratio describes the relationship between width and height. Getting that relationship right prevents accidental stretching and makes preset resizing much easier.
Lock the ratio for photographs
If the destination does not require a distorted shape, keep the aspect ratio locked while changing dimensions. The height should follow the width, or vice versa.
Common ratios such as 1:1, 4:5 and 16:9 map to different publishing contexts, but the destination requirement should decide the final choice.
Crop when the ratio does not fit
When the source and destination shapes differ, you usually have two honest choices: crop some content or accept padding. Stretching is rarely the right fix for people, products or logos.
Frequently asked questions
How do I calculate an image aspect ratio?
Reduce the width-to-height numbers by their greatest common divisor to get the simplest ratio, such as 1920×1080 becoming 16:9.
What is 16:9 used for?
16:9 is a common wide format for video frames, presentations and many digital viewing contexts.
Will changing aspect ratio crop the image?
Only a crop operation removes content. Changing dimensions alone can stretch the image if the ratio is not preserved.
Can I calculate dimensions for a fixed ratio?
Yes. Set one dimension and use the ratio to derive the other dimension.