Calculate Your Aspect Ratio
Set a ratio or pick a preset, then enter a width or height — the matching dimension updates instantly.
Aspect ratio
Common presets
Pixel dimensions
Aspect ratio
What Is an Aspect Ratio?
An aspect ratio is the proportional relationship between the
width and height of a rectangle — an image, a video frame,
a screen, or a layout. It is written as width:height (for example
16:9). Keeping the ratio fixed while you resize means your content scales
cleanly and never appears stretched, cropped, or distorted across devices.
Common Aspect Ratios
| Ratio | Decimal | Typical use |
|---|---|---|
| 16:9 | 1.78 | HD & 4K video, monitors, YouTube |
| 9:16 | 0.56 | Reels, Shorts, TikTok, Stories |
| 4:3 | 1.33 | Legacy displays, presentations |
| 1:1 | 1.00 | Square social posts, avatars |
| 3:2 | 1.50 | DSLR photography, prints |
| 21:9 | 2.33 | Ultrawide monitors, cinematic banners |
| 2.39:1 | 2.39 | Anamorphic widescreen film |
How to Use the Calculator
Enter your target aspect ratio, or tap a preset like 16:9 or 1:1.
Type the pixel width you need — the height adjusts automatically to match.
Or type a pixel height and read off the proportional width instead.
Copy the simplified ratio, decimal value, and final dimensions into your design or export.
Need More Than a Calculator?
Getting the ratio right is the easy part. Codoffer's design and engineering teams build the pixel-perfect, responsive products around it — from first mockup to a scaled, store-ready release.
Aspect Ratio Calculator — FAQs
An aspect ratio describes the proportional relationship between the width and height of an image, video, or screen. It is written as two numbers separated by a colon, such as 16:9. A 16:9 frame is 16 units wide for every 9 units tall, regardless of the actual pixel size.
Divide the width by the height to get the decimal ratio, then simplify the two numbers by their greatest common divisor. For example, 1920 × 1080 simplifies to 16:9. This calculator does both steps automatically — just type the pixel width and height.
Keep the aspect ratio fixed. Set the ratio (or pick a preset), enter the new width you need, and the calculator returns the matching height. Because both dimensions scale by the same factor, the image keeps its proportions and never looks stretched or squashed.
16:9 is the standard for modern displays, YouTube, and HD/4K video. 4:3 is used by older monitors and some presentations. 1:1 is the square format for social posts. 9:16 is vertical for Reels, Shorts, and Stories. 21:9 is ultrawide and cinematic, while 2.39:1 is the anamorphic widescreen used in film.
Yes. The calculator runs entirely in your browser, is completely free, and requires no sign-up. Use it for design mockups, video exports, responsive layouts, ad creatives, or print work as often as you like.
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