Aspect Ratio Calculator
Original Size
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Common Ratios
New Size
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Aspect Ratio Calculator — Maintain Proportions When Scaling Images & Videos
The Aspect Ratio Calculator helps you maintain the perfect proportions when resizing images, videos, or designs. Simply enter your original dimensions like 1920×1080, then modify either the width or height — the other dimension is calculated automatically to preserve the exact aspect ratio.
Key Features
- Bidirectional Calculation: Modify width to auto-calculate height, or modify height to auto-calculate width — whichever way you need.
- Common Ratio Presets: One-click presets for 16:9, 4:3, 1:1, 21:9, 3:2, and more. No need to remember exact resolutions.
- Smart Ratio Display: Automatically simplifies the aspect ratio (e.g., 1920×1080 → 16:9) so you always know the proportion you're working with.
- Real-time Results: Output updates instantly as you type, with one-click copy of the resulting dimensions.
Who Is This Tool For?
🎨 Designers: Maintain precise proportions when creating banners, social media graphics, or UI mockups at any scale.
🎬 Video Editors: Resize video canvases and export at the correct aspect ratio for YouTube (16:9), Instagram (1:1, 4:5, 9:16), and other platforms.
💻 Frontend Developers: Generate responsive image dimensions and calculate proportional CSS values without manual math.
📸 Photographers: Plan print sizes and crop ratios while preserving the original composition.
Privacy & Security
All calculations are performed entirely in your browser. Your image dimensions and resolution data never leave your device. No server uploads, no data logging — 100% private.