Ratio Calculator
Simplify a ratio to its lowest terms.
Ratio
Simplify a ratio to its lowest terms.
:
10 : 20
1 : 2
How it works
Enter the two terms of the ratio, a and b.
Both terms are divided by their greatest common divisor to reduce the ratio.
Both terms must be positive numbers — this calculator does not support zero or negative ratio terms.
Formula
a : b is simplified by dividing both terms by their greatest common divisor
Worked example: 10:20 simplifies to 1:2
More examples and edge cases
- 12:18 simplifies to 2:3
- Decimals work too: 1.5:4.5 simplifies to 1:3
- 16:9 is already in lowest terms, so it stays 16:9