Aspect Ratio Calculator
Calculate, simplify, and scale aspect ratios instantly. 16:9, 4:3, 1:1, and more.
🔒 100% client-side
Calculate Aspect Ratio
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Aspect Ratio
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Decimal
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Format
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Scale Dimensions
Enter a ratio and one dimension to get the other.
Ratio: :
Common presets:
Common Aspect Ratios
| Ratio | Decimal | Common use |
|---|---|---|
| 16:9 | 1.7778 | HD/4K video, YouTube, most monitors |
| 4:3 | 1.3333 | Old TV, iPad, photography |
| 1:1 | 1.0000 | Instagram square, profile pictures |
| 21:9 | 2.3333 | Ultrawide monitors, cinematic film |
| 3:2 | 1.5000 | DSLR cameras, 35mm film |
| 9:16 | 0.5625 | Portrait video, TikTok, Instagram Reels |
| 16:10 | 1.6000 | MacBook, older widescreen laptops |
| 4:5 | 0.8000 | Instagram portrait posts |
About Aspect Ratio Calculator
Aspect Ratio Calculator instantly reduces any width and height to their simplest ratio (e.g. 1920x1080 becomes 16:9), then lets you scale dimensions proportionally by entering one side. Useful for designers, video editors, developers, and anyone working with responsive images or fixed-format media. Everything runs in your browser — no data is sent anywhere, no sign-up needed.