Ratio Calculator

Modify the values and click the calculate button to use

Please provide any three values below to calculate the fourth in the ratio A:B = C:D.

A   B   C   D
 :   =   : 

Ratio Scaling Calculator

: times = ?

Related:Fraction Calculator

What is Ratio?

A ratio tells you how many times one amount contains another. The concept shows up in everyday life and is pretty straightforward. Picture a child receiving only half as many cookies as his sister. He may not be able to state the math, but his obvious complaint will reveal that he senses the distribution as a 1:2 split.

Usually a ratio is written with two numbers separated by a colon, like "1:2", or spoken as "one to two". It can also appear as the fraction ½. The ratio indicates the factor you must multiply the denominator by to reach the numerator – in this case, multiplying 2 by ½ gives 1. The relationship becomes clearer when the first number is larger, e.g., 2:1 means two contains one twice. Ratios may also involve more than two terms.

We meet ratios in countless daily situations: screen aspect ratios, scaled maps and models, recipes, probability calculations, and financial rates. For instance, if someone plans to bake five cakes and each cake calls for a butter‑sugar‑flour proportion of 1:2:3, the total amounts are easy to work out. Multiplying the base ratio by five gives 5:10:15, which can then be converted into the actual weights of butter, sugar, and flour needed for the batch.

Typical Aspect Ratios and Sizes of Screens and Videos

An aspect ratio compares the dimensions of a shape in different directions. For a rectangle it is simply the width divided by the height. While aspect ratios are useful for tire specifications, paper standards, and photographic prints, they are most commonly discussed in the context of computer monitors, smartphones, and video formats. Below you will find a table of typical screen and video resolutions together with their corresponding 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
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