Aspect Ratio Calculator
Enter your original width and height, then change one dimension — the calculator keeps the proportions perfect. Comes with presets for YouTube, Instagram, TikTok and print.
Ratio: 16:9
Frequently asked questions
What is aspect ratio?
Aspect ratio is the proportional relationship between an image’s width and height, written as W:H (e.g. 16:9). It describes the *shape* of the image, not its size — a 1920×1080 video and a 640×360 video both have a 16:9 ratio.
What aspect ratio should I use for YouTube, Instagram and print?
YouTube and TV content: 16:9. Instagram feed posts: 1:1 (square) or 4:5 (portrait). Instagram/Facebook Stories, Reels and TikTok: 9:16. Classic photography and 35mm film: 3:2. Cinema: 2.39:1. US letter paper: 8.5:11. Choose based on where the image will be displayed.
Why does my resized image look stretched?
Because the width and height were changed by different proportions, breaking the original ratio. Always scale both dimensions by the same factor — enter your original size and one new dimension above, and the calculator gives you the matching second dimension automatically.