How it works
An aspect ratio is just width divided by height. To resize an image or video without distortion, both dimensions must scale by the same factor. The formula this calculator uses:
new height = new width × (original height ÷ original width)
Type in either new dimension and the tool solves the other one, rounding to the nearest whole pixel — because a 1279.6-pixel-wide video makes nobody happy.
Common aspect ratios in 2026
| Ratio | Used for | Common resolutions |
|---|---|---|
| 16:9 | YouTube, TV, presentations | 1280×720 · 1920×1080 · 3840×2160 |
| 9:16 | TikTok, Reels, Shorts, Stories | 1080×1920 · 720×1280 |
| 1:1 | Square posts, profile pictures | 1080×1080 · 800×800 |
| 4:5 | Instagram portrait posts | 1080×1350 |
| 4:3 | Older video, iPad screens | 1024×768 · 1600×1200 |
| 3:2 | DSLR / mirrorless photos | 3000×2000 · 6000×4000 |
| 21:9 | Cinematic video, ultrawide | 2560×1080 · 3440×1440 |
Making graphics for a specific platform? Grab the exact pixel sizes from our Social Media Image Sizes cheat sheet.
FAQ
What aspect ratio is 1920×1080?
16:9. Divide both numbers by their greatest common divisor (120) and you get 16 and 9. It's the standard for YouTube and almost all modern displays.
How do I convert 16:9 to 9:16 without cropping?
You can't — they're opposite orientations, so something has to give. Either crop the sides (most vertical-video workflows do this), add blurred padding bars, or reframe the shot around your subject.
Why does my resized image look blurry?
Scaling up adds pixels that were never there. Keeping the correct aspect ratio prevents distortion, but only an AI upscaler or a higher-resolution source prevents softness when enlarging.