Does this crop or resize my actual image?

No. This only calculates dimensions; use the Image Resizer tool to resize an actual image file.

Home/Utilities/Aspect Ratio Calculator

UtilitiesReady to use

Aspect Ratio Calculator

Calculate a missing width or height from a known aspect ratio, or find the ratio between two dimensions.

Documentation

Interactive workspace

No account required

Aspect Ratio Calculator

WidthRatio widthRatio height

Calculated height

1080px

What is Aspect Ratio Calculator?

Calculate a missing width or height from a known aspect ratio, or find the ratio between two dimensions.

How it works

SiteIndex scales a known width or height using your target ratio to calculate the missing dimension, and can also reduce two dimensions to their simplest whole-number ratio.

Where a network request is required, SiteIndex validates public HTTP/HTTPS targets before making the request.

Common uses

Find the correct height for a banner at a fixed width and ratio.
Check whether an image matches a common ratio like 16:9 or 4:3.
Resize a design proportionally without distorting it.

Limitations

Results depend on the browser, network, input, and external service involved.
This tool is informational and does not replace specialist diagnostics or professional advice.

FAQ

Does this crop or resize my actual image?: No. This only calculates dimensions; use the Image Resizer tool to resize an actual image file.

Related tools

Golden Ratio Calculator

Utilities