Ratio Calculator
Simplify a two-part ratio to its lowest whole-number terms.
Simplified ratio
Worked example
12 : 18 simplifies to 2 : 3, because 6 is the largest number that divides both parts exactly.
How it works
Simplify reduces a two-part ratio to its simplest whole-number form. Either part may be zero as long as the other is not, so 0 : 5 simplifies to 0 : 1 and 5 : 0 to 1 : 0; two zero parts are rejected. A single negative part keeps its sign, while two negative parts give the equivalent positive ratio. Solve a proportion finds a missing value across two equal ratios (A : B = C : D) by cross-multiplication. Scale multiplies both parts of a ratio by the same factor. Equivalent-ratio listing, splitting a total by a ratio, and comparing two ratios are not yet available.
A result written as a plain number is exact. A result starting with “≈” has been rounded to 10 significant figures, because its exact decimal never ends or is too long to read comfortably. When an exact value is long, its full digits are shown underneath. The calculation itself is never rounded: only the display is.
What this result means
The result depends on the mode: a simplified ratio, the missing value in a proportion, or a scaled ratio.
Assumptions and limitations
- Simplify mode requires whole numbers; Solve proportion and Scale accept decimals.
- In Simplify mode a part may be zero if the other is not (0 : 5 becomes 0 : 1); two zero parts are rejected, and a single negative part keeps its sign.
- There is no equivalent-ratio list, no splitting a total by a ratio, and no side-by-side ratio comparison mode.