Aspect Ratio Finder
Find your image’s exact aspect ratio in seconds, or calculate the right dimensions for a ratio you already know like 16:9 or 4:5. No uploads, no guesswork, just accurate numbers instantly.
Find Your Image’s Aspect Ratio
Upload an image to auto-fill its size, or type the dimensions in yourself.
Calculate Dimensions From a Ratio
Know the ratio you need? Enter it plus one dimension to get the other.
How to Use the Aspect Ratio Finder
Enter your size
Upload an image and the tool reads its dimensions automatically, or type in the width and height yourself.
See your ratio
It’s simplified instantly (like 1920×1080 becoming 16:9), with the closest common ratio if there’s a match.
Or reverse it
Know the ratio you need? Enter it plus one dimension, and get the matching width or height.
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the relationship between an image’s width and height, written as two numbers like 16:9 or 4:3. It describes the shape of the image regardless of its actual size in pixels a 1920×1080 image and a 640×360 image are both 16:9.
How do I find the aspect ratio of my image?
Upload your image using the tool above, and it will automatically read the width and height, then calculate and simplify the ratio for you. You can also type the dimensions in manually if you already know them.
What’s the difference between aspect ratio and resolution?
Resolution is the actual pixel size of an image (like 1920×1080). Aspect ratio is the shape that size creates (16:9, in that example). Two images can have completely different resolutions but the same aspect ratio.
What aspect ratio should I use for Instagram?
It depends on the post type, square posts are typically 1:1, portrait posts are commonly 4:5, and Stories/Reels are 9:16. This can change as platforms update their specs, so it’s worth double-checking current requirements if precision matters.
What aspect ratio is a standard photo?
Traditional 35mm photography and most DSLR/phone cameras shoot in 3:2 or 4:3, depending on the camera. Widescreen video and most modern monitors use 16:9.
Can I use this tool to figure out what size to resize my image to?
Yes, use the second calculator on this page. Enter the ratio you need (like 16:9) along with one dimension you already know, and it calculates the matching width or height for you.
Does this tool change or resize my actual image?
No, this tool only calculates numbers. It doesn’t modify your image file. If you need to actually resize or crop your image to a specific ratio, use the Resize Image or Crop Image tools instead.