Aspect ratio calculator
Enter the width and height of an image or video and a new width or height to calculate the original aspect ratio and the other dimension that preserves it. Plan the dimensions before resizing, then copy the results or save them as text. The image itself is not changed, and calculated dimensions are rounded to whole px.
What you can do
Convert width and height to a ratio
Display the original dimensions as a reduced integer ratio, such as 16:9 for 1920×1080.
Calculate the other dimension
Specify a new width or height to calculate the other dimension while preserving the ratio.
How to use
Enter the original dimensions
Enter an image or video’s width and height in pixels.
Specify the new width or height
Choose which side to use as the reference and enter its new pixel count.
Check the calculated results
Press the calculate button and check the ratio and new dimensions. You can also copy results or save them as text.
Useful when
Find a resolution’s aspect ratio
Check an image or video’s width and height as a ratio such as 16:9.
Change dimensions while keeping the shape
Calculate dimensions that preserve the aspect ratio, such as the height when reducing the width.
Aspect ratio and pixel dimensions
A ratio describing width and height
Aspect ratio is written in width:height order. 16:9 means a shape with a width of 16 and height of 9.
Dimensions can differ at the same ratio
1920×1080 and 1280×720 are both 16:9. Ratio describes the shape; pixel dimensions describe the actual width and height.
Rounding to whole pixels
The calculated other dimension is rounded to a whole px. For example, at 3:2 with a width of 1000px, the height changes from about 666.67px to 667px.
Frequently asked questions
What ratio is 1920×1080?
Reducing 1920 and 1080 by dividing both by the same number gives 16:9.
Can I also resize an image file?
This screen calculates numbers. To change the image itself, use an image editing tool such as the image aspect ratio viewer and changer.
Is the result’s ratio the ratio of the new dimensions?
The displayed ratio comes from the original width and height. New dimensions are rounded, so their ratio may differ slightly.
Input & results
- Input
- Uses width, height and the dimension you specify for resizing.
- Results
- Calculated aspect ratio and dimensions. The image file is not changed.