Aspect Ratio Calculator
Maintain perfect proportions across all screens. Calculate new dimensions while preserving the original aspect ratio instantly.
Visual Representation
Your resulting image will be 1280x720. Perfect for social media uploads or UI assets.
Why it matters?
Uploading images with incorrect aspect ratios leads to unappealing crops or "black bars" (letterboxing). This tool ensures your assets match the exact ratio required by modern platforms.
Built With Care
“Aspect ratios are expressed as the greatest common divisor of width and height. This tool uses Euclidean GCD to produce clean, simplified ratios like 16:9 or 4:3, ensuring your dimensions map correctly to platform requirements.”
Aspect Ratio Calculator
Enter a width and height to get the simplified aspect ratio. Also works backwards — enter a target ratio and one dimension to calculate the other.
- 1Enter the 'Original Dimensions' (width and height) of your image or container.
- 2View the calculated aspect ratio in the highlighted box.
- 3Enter one dimension in the 'New Dimensions' section.
- 4The other dimension will update automatically to maintain the original ratio.
- 5Use the quick presets for common dimensions like 4K, 1080p, or Instagram formats.
- Linked Inputs: Real-time synchronization of width and height dimensions.
- Visual Preview: Dynamic scaling box to represent the specified ratio.
- Common Presets: Access standard sizes for social media and video production.
- GCD Calculation: Precision math ensuring clean integer ratio representation.
- Instant Calculation: Ratios update in real time as you enter dimensions.
Real Ways People Use This
Social Media Resizing
Convert landscape photos to Instagram portrait (4:5), square (1:1), or story (9:16) formats without cropping.
Video Production
Maintain correct aspect ratios when exporting footage for YouTube (16:9), TikTok (9:16), or ultrawide monitors (21:9).
Responsive Web Design
Calculate container dimensions that preserve aspect ratio across breakpoints for image galleries and hero sections.
Print & Publishing
Scale images to standard print ratios like 3:2, 4:5, or 5:7 for magazines, posters, and books.
- Results are rounded to the nearest pixel — very small target dimensions may show slight rounding differences.
- This tool calculates proportional dimensions only; it does not crop or compress your actual image file.
- 1Enter your source dimensions and confirm the ratio matches your target platform.
- 2Input one new dimension and verify the calculated partner dimension looks correct.
- 3Use the presets to quickly load common dimensions before exporting.