How it works
A ratio is simplified by dividing both sides by their greatest common divisor (GCD), the largest number that divides evenly into both.
Decimal values are handled by first scaling both sides up to whole numbers by the same amount, so the ratio between them is unchanged, then simplifying as usual.
The percentage share divides each simplified side by the total of both sides.
Formula: Divide both sides of the ratio by their greatest common divisor.
Examples
A whole-number ratio
12 : 18 shares a greatest common divisor of 6, so it simplifies to 2 : 3.
A decimal ratio
1.5 : 2.5 scales up to 15 : 25, which simplifies to 3 : 5.
Percentage share
A ratio of 2 : 3 is a 40% : 60% share of the total (2 and 3 add up to 5, and 2 is 40% of 5).
Things to keep in mind
- Both sides of a ratio must be zero or positive: a ratio of negative quantities is not a meaningful share of a whole, so the calculator rejects negative input rather than showing a negative percentage share.
- A ratio of 0 : 0 has no meaningful simplified form and is rejected; a ratio with exactly one zero side, such as 0 : 5, simplifies to 0 : 1.
- Values with a very large number of decimal places may be too precise to simplify exactly and are rejected rather than silently rounded.