🔢 Number Tools
Aspect Ratio Calculator
Find missing image dimensions from a ratio, or calculate the aspect ratio from width and height. Common ratio presets included.
Aspect Ratio
Enter the ratio and one dimension to find the other
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Common aspect ratios — click to load
${[['16:9','HD Video / Widescreen'],['4:3','Old TV / iPad'],['1:1','Square / Instagram'],['21:9','Ultrawide Monitor'],['9:16','Mobile / Stories'],['2:1','Panoramic'],['3:2','DSLR / 35mm Film'],['4:5','Portrait Photo'],['5:4','Monitor'],['8:5','Widescreen Laptop']].map(([r,l])=>
``).join('')}
How to use the Aspect Ratio
1
Find a missing dimension
Enter a ratio (e.g. 16:9) and either the width or the height. The calculator finds the missing dimension that maintains the exact ratio. Useful for scaling images, designing for specific screen sizes, or creating thumbnails at a required aspect ratio.
2
Find the ratio from dimensions
Enter width and height to see the simplified ratio. The result is shown both as a whole-number ratio (e.g. 16:9) and as a decimal (e.g. 1.78:1). Use the common ratios panel to quickly load any standard screen or photo format.