Calculate height
height = width × ratio height ÷ ratio widthFor 1920px at 16:9: 1920 × 9 ÷ 16 = 1080px.
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Ratio finder, scaler, and crop preview
Aspect Ratio Calculator
Find an aspect ratio from width and height, calculate matching dimensions, and crop or fit local images for screen, video, and social media formats.
Find, resize, or crop dimensions
Find a ratio, scale dimensions, or preview how an image will crop or fit. All calculations and image processing stay in this browser.
Free · no upload · no account
Width and height to ratio
What is my aspect ratio?
Enter any image, screen, video, or design dimensions. The result is simplified with the greatest common divisor and compared with familiar formats.
16:9
- Simplified ratio
- 16:9
- Decimal
- 1.778:1
- Orientation
- Landscape
- Nearest common format
- 16:9 · Widescreen video
aspect-ratio: 16 / 9;Ratio to matching dimensions
Resize without stretching
Matching dimensions
1,920 × 1,080
16:9 · 1.778:1
16:9
aspect-ratio: 16 / 9;Private image aspect ratio preview
Crop to fill or fit with padding
Choose a target ratio and optional local JPG, PNG, or WebP. The file stays in browser memory and is never sent to the server.
No file selected. Images are processed only in this browser.
Your private preview appears here
The frame updates before a file is selected, so layout remains stable.
1,920 × 1,080 · 16:9
Crop to fill: edges may be trimmed.
Direct answer
What is aspect ratio?
Aspect ratio is the proportional relationship between width and height, written as width:height. A 16:9 image is 16 units wide for every 9 units tall. The ratio describes shape, while resolution describes the exact number of pixels, such as 1920 × 1080.
Calculate width
width = height × ratio width ÷ ratio heightFor 1080px at 16:9: 1080 × 16 ÷ 9 = 1920px.
| Concept | Example | What it tells you |
|---|---|---|
| Aspect ratio | 16:9 | The proportional shape of the frame. |
| Resolution | 1920 × 1080 | The exact pixel dimensions. |
| Orientation | Landscape | Whether width is greater than height. |
| CSS | aspect-ratio: 16 / 9; | The preferred box proportion in responsive layout. |
How to use it
Aspect Ratio Calculator guide
Use the aspect ratio calculator to simplify width and height into a ratio, calculate a missing dimension, or preview how a local image will crop or fit a target frame. It supports common image, video, screen, thumbnail, banner, and social formats without sending the image to a server.
Limitation: Aspect ratio keeps shape, not file quality. You still need to choose the right image format, compression, safe area, and platform-specific crop rules before publishing.
Recommended workflow
- 1. Choose Find ratio when both dimensions are known, or Scale dimensions when one side is missing.
- 2. Choose a common preset or enter a custom ratio, then select the pixel rounding rule required by the destination.
- 3. Use Crop or fit image to compare a filled crop with a padded frame; the optional JPG, PNG, or WebP stays in the browser.
Practical examples
1920 by 1080 is a 16:9 widescreen video or presentation frame.
1080 by 1920 is a 9:16 vertical video frame for Shorts, Reels, TikTok, and stories.
1080 by 1350 is a 4:5 portrait feed size that keeps more vertical space than a square post.
Frequently asked questions
How do I calculate aspect ratio from width and height?
Divide both dimensions by their greatest common factor. The calculator does that work for common creative and screen sizes so you can copy the matching dimension quickly.
Which aspect ratio should I use for YouTube?
Use 16:9 for normal YouTube videos and thumbnails. Use 9:16 for YouTube Shorts.
Does changing aspect ratio crop my image?
Changing ratio may require cropping or adding empty space. Scaling alone keeps the whole image but can leave it too wide or too tall for the target placement.
Helpful references
Related ratio and screen size resources
Use these tools when aspect ratio work depends on screen dimensions, viewport size, or display comparison.
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Device references
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Guide collection
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Use these supporting guides to understand the tool result and next testing steps.
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