memegenAspect Ratio Calculator
Work out new width and height values that keep the same aspect ratio — no distortion, no guesswork. Enter your original dimensions, then type either a new width or a new height and the other fills in automatically. Pick a common ratio like 16:9 or 1:1 to start from a preset. Everything runs on this page; nothing is uploaded.
Updated June 2026
What is an aspect ratio?
Aspect ratio is the proportional relationship between an image's width and height, written as two numbers like 16:9 or 4:3. It describes shape, not size: a 1280×720 image and a 1920×1080 image are both 16:9, just at different resolutions.
Keeping the ratio constant when you resize is what stops images from looking stretched or squashed. This calculator does that math for you — change one dimension and it derives the matching value for the other.
Common aspect ratios
A few ratios cover most screens, photos, and social platforms:
| Ratio | Used for | Example size |
|---|---|---|
| 16:9 | Video, YouTube, monitors | 1920 × 1080 |
| 9:16 | Stories, Reels, TikTok | 1080 × 1920 |
| 1:1 | Square posts, avatars | 1080 × 1080 |
| 4:3 | Classic photos, slides | 1024 × 768 |
| 3:2 | DSLR photos, prints | 1620 × 1080 |
| 21:9 | Ultrawide displays | 2560 × 1080 |
Frequently asked questions
How do I calculate a new size with the same aspect ratio?
Enter your original width and height to define the ratio, then type the new width you want — the calculator fills in the matching height automatically (and vice versa), so the proportions stay identical.
What does a ratio like 16:9 actually mean?
It means for every 16 units of width there are 9 units of height. It describes the shape of the image, not its pixel size — many resolutions (1280×720, 1920×1080, 3840×2160) all share the 16:9 ratio.
How do I find the aspect ratio of an existing image?
Enter its width and height and the calculator shows the simplified ratio (for example, 1920×1080 simplifies to 16:9) along with the exact decimal ratio.
Does this work for video as well as photos?
Yes. Aspect ratio is the same concept for any rectangular media, so the calculator works equally well for video frames, screen resolutions, photos, and print sizes.
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