Simplify a ratio to its lowest terms, or find a missing value that keeps two ratios equivalent (A:B = C:D).
Ratio Calculator
LiveSimplified ratio
2:3
In "Solve" mode, leave whichever value you want to find blank.
The formulas
Simplify: A:B = (A/GCD) : (B/GCD)
Solve: A:B = C:D -> D = (C x B) / A or C = (A x D) / B
Example
Simplify 8:12 - GCD of 8 and 12 is 4, so 8:12 = 2:3. Solving 2:3 = 10:D gives D = (3 x 10) / 2 = 15.
Step-by-step guide
- Choose "Simplify" to reduce a ratio to lowest terms, or "Solve" to find a missing value in an equivalent ratio.
- Enter your known values.
- Read the result.
Common mistakes
Mixing up the order - 2:3 is not the same as 3:2, so keep the values in the same order as your original ratio.
Adding instead of scaling - equivalent ratios are found by multiplying or dividing both numbers by the same factor, not adding the same amount.
Frequently asked questions
What's the difference between a ratio and a fraction?
A ratio compares two quantities (like 2 cups flour to 3 cups sugar), while a fraction typically represents a part of a whole. They use the same math, but describe different real-world relationships.
Can I use ratios with three or more terms?
This calculator handles two-term ratios (A:B). For a three-term ratio like 2:3:5, simplify by dividing all three numbers by their greatest common factor.
Where are ratios commonly used?
Recipe scaling, map scales, mixing solutions, aspect ratios for images and video, and financial ratios are all common everyday uses.
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