Aspect Ratio Calculator
Calculate dimensions while maintaining aspect ratios for images and videos
Preview
Current Ratio: 16:9
Custom Ratio
Presets
1920 × 1080
Ratio: 16:9
All calculations happen in your browser.
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Add this tool to your website with customizable styling
How to Use
- 1 Enter your dimensions — Input the width or height you want to use. The calculator will maintain your chosen aspect ratio.
- 2 Select a preset ratio — Choose from common ratios like 16:9 (widescreen), 4:3 (standard), 1:1 (square), or enter a custom ratio.
- 3 Lock width or height — Lock one dimension and the other will automatically calculate to maintain the ratio.
- 4 Copy the result — Use the Copy button to copy the dimensions. Use the Swap button to quickly switch width and height.
Frequently Asked Questions
What is aspect ratio?
Aspect ratio is the proportional relationship between width and height, expressed as X:Y. For example, 16:9 means 16 units wide for every 9 units tall. The actual pixel dimensions can vary, but the ratio stays constant.
Why is maintaining aspect ratio important?
Maintaining aspect ratio prevents images and videos from looking stretched or squished. It's essential for responsive design, video editing, and ensuring content displays correctly across different screen sizes.
What's the most common aspect ratio for video?
16:9 (widescreen) is the standard for HD and 4K video, YouTube, and most monitors. 4:3 was the old TV standard. 9:16 is used for mobile/portrait videos like TikTok and Instagram Stories.
How do I resize an image while keeping aspect ratio?
Enter your current dimensions, select your desired ratio or lock one dimension (width or height), then change the other value. The calculator automatically adjusts the locked dimension to maintain the ratio.