Ratio Calculator
Solve ratio equations, scale ratios up or down, and compare two ratios easily.
Solve for Missing Value in A : B = C : D
Leave one field empty (or place 'x' in it) to calculate the missing value.
Understanding Ratios & Proportions
A ratio shows the relative sizes of two or more values. A proportion is an equation stating that two ratios are equal.
If A / B = C / D, then A × D = B × C
A = (B × C) / D
New Ratio = (A × Factor) : (B × Factor)
Frequently Asked Questions (FAQs)
To solve for an unknown value in a proportion like $A:B = C:D$, use cross-multiplication: multiply the diagonally opposite known values and divide by the remaining known value.
Scaling means multiplying or dividing both sides of the ratio by the same non-zero number to maintain the same proportion at a different total size.
Divide both parts of the ratio by their greatest common divisor (GCD) until no further simplification is possible.
Yes. It can determine whether two ratios are equal, greater than, or less than each other by comparing their proportional values.
Ratios are commonly used in cooking, finance, construction, engineering, map scales, photography, and many scientific calculations.