Aspect Ratio Converter
How to use the converter
Fill in the x/y values for the base ratio, and then either the x or y value for the result ratio. The remaining value will automatically be calculated. For example, if you have an image that is 800x600, and you need to size it down to a width of 525, you would enter 800/600 as the base ratio, and 525 for the x value (width) of the result ratio. You'll notice the y value of the result ratio will automatically be calculated as 393.75. You'll typically want to round this value up to the nearest whole number (394) for use in image tags, video embed codes, etc.
16 x 9 Aspect Ratio
16 x 9 has become the most common aspect ratio used in televisions (it is also the international standard for HDTV). To transform your current ratio to 16 x 9 using our calculator, simply enter your current ratio in the base ratio field (ie. for 640x480 you would enter 640 in the X field and 480 in the Y field). You'll notice the result ratio is 12.8 x 9.6. Change the 12.8 value to 16, and you get a result ratio of 16 x 12. Now, that means that your current ratio is 16 x 12, whereas your target ratio is 16 x 9. In other words, your image is too tall. To resize it to 16 x 9, you can either chop off 3 units of height from the top of the image or the bottom of the image, or 1.5 units from both the top and the bottom. To find out how many units 640 is, simply multiply 640 by (9/16 or 0.5625) to get 360. To confirm that your new ratio is 16 x 9, simply plug in 640 x 360 in the base ratio fields. You'll see the result ratio field produce our target aspect ratio of 16 x 9. Alternatively, with photo editing software such as Adobe Photoshop Elements, you can resize the image and scale the size while constraining the proportions (ie. you don't need to lose any of the image).
4 x 3 Aspect Ratio
The 4 x 3 aspect ratio was used historically since the invention of motion pictures and computers (1940's and 50's). When cinema attendance dropped, Hollywood created a widescreen (16 x 9) aspect ratio to differentiate film from tv. As you read above, however, that is now the standard for home theater and PC monitors as well. To calculate a 4 x 3 aspect ratio, use the same approach we describe above, but substitute in the 4 x 3 ratio. You can also convert a 4 x 3 ratio to 16 x 9 using this method, or vice versa.