Aspect Ratio Calculator

The aspect ratio is the proportion between width and height. Keep it the same when you resize and the picture will not stretch. Enter a width and height to see the ratio in its simplest form (1920 × 1080 is 16:9), then enter a new width or height to get the matching other side.

How to use Aspect Ratio Calculator

1. Enter the original width and height in pixels (or any unit).
2. Read the simplified ratio and the decimal ratio.
3. Enter a new width, or a new height, to get the other side at the same ratio.

When it comes in handy

• Resizing images and video for social media without black bars.
• Working out thumbnail sizes for a web layout.
• Checking whether a screen or print size matches a photo.

Frequently asked questions

What are the common ratios?

16:9 for HD video and most screens, 4:3 for older screens and many cameras, 1:1 for square posts, 9:16 for Stories, Reels and Shorts, 3:2 for DSLR photos and 21:9 for ultrawide monitors.

Why is my ratio something odd like 683:384?

Some sizes are not an exact standard ratio. 1366 × 768 simplifies to 683:384, which is roughly 16:9 (1.78). The decimal ratio helps compare them.