Aspect Ratio Calculator
Work out the right pixel dimensions to keep an image or video in proportion. Set your target aspect ratio, such as 16:9 for widescreen video or 4:3 for classic photos, then type a width and the calculator fills in the matching height, or type a height to get the width. This saves you from squashed or stretched media when you resize, crop for a thumbnail, or plan a layout. You can also enter a custom ratio for anything unusual. Because it works both directions, you always land on the exact pair of dimensions that preserves the shape you want. It runs entirely in your browser with instant results as you type, so there is nothing to install and no waiting, and none of your values are ever sent anywhere.
How to use Aspect Ratio Calculator
- Choose or enter the target ratio.
- Enter either the width or the height.
- Read the matching dimension it calculates.
- Use both values to resize in proportion.
Frequently asked questions
How does it keep dimensions in proportion?
You enter a width or height and a target ratio, and it calculates the matching dimension so the image stays proportional.
Which ratios can I use?
You can use common ratios like 16:9 or 4:3, or set your own, and the tool solves for the missing side.
Why does keeping the ratio matter?
Matching the ratio prevents images or videos from stretching or squashing when you resize them.
What is Aspect Ratio Calculator?
Work out the right pixel dimensions to keep an image or video in proportion. Set your target aspect ratio, such as 16:9 for widescreen video or 4:3 for classic photos, then type a width and the calculator fills in the matching height, or type a height to get the width.
Is Aspect Ratio Calculator free to use?
Yes. Aspect Ratio Calculator is completely free, with no sign-up and no usage limits.
Does Aspect Ratio Calculator work in a web browser?
Yes. Aspect Ratio Calculator runs in any modern web browser. There is nothing to download or install.
Is my data private with Aspect Ratio Calculator?
Yes. Aspect Ratio Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.
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