Aspect Ratio Calculator
Calculate the missing width or height for any ratio.
Set your aspect ratio
How do I use Aspect ratio calculator?
Calculate a missing dimension using a width-to-height ratio. At 16:9, multiply a known width by 9 and divide by 16 to get the height. The result is rounded to a whole pixel.
- Choose a common ratio or enter your own width-to-height ratio.
- Choose whether you know the width or height, then enter its pixel value.
- Read or copy the calculated dimensions. The missing dimension is rounded to the nearest whole pixel.
Still JPG, PNG, and WebP images are supported. Each image can be up to 25 MB, 24 megapixels, and 8,192 pixels on either side. These limits apply when you process an image, not when you calculate dimensions.
What should I know before using this tool?
How do I calculate height from width?
Multiply the known width by the ratio height, then divide by the ratio width. At 16:9, a width of 1920 pixels gives a height of 1080 pixels.
Does this tool resize an image?
This calculator gives you the dimensions. To change an image file, enter those dimensions in Resize image.
Why is the result rounded?
Image dimensions must be whole pixels. Some combinations of ratio and known dimension produce fractions, so the result is rounded and may differ slightly from the exact mathematical ratio.
Where can I learn more about image formats and browser tools?
Aspect ratios express width relative to height. MDN illustrates ratios such as 1:1 and 16:9 in browser layouts. MDN: Aspect ratio.