Ratio Calculator

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Ratio Scaling Calculator

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Related:Fraction Calculator


A ratio is a quantitative relationship between two numbers that describes how many times one value can contain another. Applications of ratios are fairly ubiquitous, and the concept of ratios is quite intuitive. This could easily be demonstrated by giving a child half as many cookies as his sister. While the child may not be able to voice the injustice using ratios, the raucous protestations that would undoubtedly ensue should make it immediately obvious that he is well aware he has received 1:2 as many cookies as his sister, conceptually, if not mathematically.

As shown above, ratios are often expressed as two numbers separated by a colon. They can also be written as "1 to 2" or as a fraction ½. In simple terms, the ratio represents the number that needs to be multiplied by the denominator in order to yield the numerator. In this case, ½. This is clearer if the first number is larger than the second, i.e. with the ratio 2:1, 2 can contain 1, 2 times. It is also possible to have ratios that have more than two terms.

Ratios are common in many daily applications including: aspect ratios for screens, describing maps and models as a scaled down version of their actual size, in baking and cooking, when discussing the odds of something occurring, or to describe rates, such as in finance. If, for example, a person wanted to make 5 cakes, each of which required a 1:2:3 ratio of butter:sugar:flour, and wanted to determine the total amount of butter, sugar, and flour that is necessary, it would be simple to compute given the ratio. Increasing the ratio by five times yields a 5:10:15 ratio, and this can be multiplied by whatever the actual amount of sugar, flour, and butter are used in the actual cake recipe.

Typical Aspect Ratios and Sizes of Screens and Videos

The aspect ratio is the ratio of a geometric shape's sizes in different dimensions. In the case of a rectangle, the aspect ratio is that of its width to its height. Although aspect ratios are widely used in applications such as tire sizing, paper sizing, and standard photographic print sizes, some of the most frequent uses of aspect ratios involve computer screen dimensions, mobile phone screens, and video sizes. As such, below is a list of typical computer screen/video resolutions and aspect ratios.

NameAspect ratioWidth (pixel)Height (pixel)
480p3:2720480
576p5:4720576
720p16:91280720
1080p16:919201080
2160p (4K UHD)16:938402160
4320p (8K UHD)16:976804320
8640p16:9153608640
SVGA4:3800600
WSVGA~17:101024600
XGA4:31024768
XGA+4:31152864
WXGA16:91280720
WXGA5:31280768
WXGA16:101280800
SXGA (UVGA)4:31280960
SXGA5:412801024
HD~16:91360768
HD~16:91366768
SXGA+4:314001050
WXGA+16:101440900
HD+16:91600900
UXGA4:316001200
WSXGA+16:1016801050
FHD16:919201080
WUXGA16:1019201200
QWXGA16:920481152
WQHD16:925601440
WQXGA16:1025601600