Free Online Aspect Ratio Calculator
Calculate aspect ratios and resize dimensions proportionally with HubKit's aspect ratio calculator. Enter width and height to find the ratio, or set a target dimension to calculate the other while maintaining the aspect ratio. Essential for responsive design, video production, image resizing, and CSS layout.
How to Use
Enter width and height values to calculate the aspect ratio. Or enter one dimension with a target ratio to calculate the other. The tool shows the simplified ratio and lets you resize while maintaining proportions.
Features
- Calculate aspect ratio from any dimensions
- Resize proportionally by changing one dimension
- Common presets: 16:9, 4:3, 1:1, 21:9, etc.
- Pixel and percentage-based calculations
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the proportional relationship between width and height. 16:9 means for every 16 units of width there are 9 units of height. It is used in displays, images, videos, and responsive design.
What is the most common aspect ratio for video?
16:9 (widescreen) is the standard for YouTube, Twitch, and most modern displays. 9:16 is used for vertical video on TikTok and Instagram Stories. 4:3 was the old TV standard.
How do I maintain aspect ratio when resizing images?
Set one dimension (width or height) and calculate the other using the aspect ratio. For example, to resize a 1920×1080 (16:9) image to 1280px wide: 1280 ÷ (16/9) = 720px tall.