Aspect Ratio Calculator
Calculate aspect ratios and find dimensions that maintain a given ratio.
About This Aspect Ratio Calculator
This free aspect ratio calculator helps you quickly determine the aspect ratio of any dimensions or calculate missing dimensions from a known ratio. Whether you're working with video resolutions, image crops, or responsive design layouts, this tool provides instant results with a visual preview.
How to Use
- Choose your mode: "Dimensions → Ratio" to find the ratio from width and height, or "Ratio → Dimension" to find a missing dimension.
- In the first mode, enter your width and height to see the simplified aspect ratio.
- In the second mode, select a preset or enter a custom ratio, then provide one dimension to calculate the other.
- Use the visual preview to see the proportions of your aspect ratio.
Frequently Asked Questions
What is an aspect ratio?
An aspect ratio is the proportional relationship between width and height. It's expressed as two numbers separated by a colon, such as 16:9. This means for every 16 units of width, there are 9 units of height.
What is the most common aspect ratio?
16:9 is the most common aspect ratio for displays, TVs, and video content. It's the standard for HD (1920×1080), 4K (3840×2160), and most YouTube videos.
How is the aspect ratio calculated?
The tool finds the Greatest Common Divisor (GCD) of the width and height, then divides both values by the GCD to get the simplified ratio. For example, 1920÷120 = 16 and 1080÷120 = 9, giving a 16:9 ratio.
What aspect ratio should I use for social media?
Different platforms prefer different ratios: Instagram posts use 1:1 or 4:5, Instagram Stories and TikTok use 9:16, YouTube thumbnails use 16:9, and Facebook posts work well with 1.91:1 or 1:1.