Ratio Calculator
Simplify a ratio to its lowest terms, or solve a proportion a : b = c : ?. Shows the steps.
Ratio Calculator
12 : 8 = 3 : 2 Divide both parts by their greatest common divisor (4).
What This Ratio Calculator Does
Simplify a ratio to its lowest terms, or solve a proportion to find a missing value.
How It Works
simplify: divide both parts by their greatest common divisor
proportion: in a : b = c : ?, the missing value = (b x c) / aHow to Use It
- Choose simplify a ratio or solve a proportion.
- Enter the parts (a third value
cappears for proportions). - Read the simplified ratio, or the solved proportion.
Worked Examples
Simplifying:
| Ratio | Simplest form |
|---|---|
| 12 : 8 | 3 : 2 |
| 10 : 5 | 2 : 1 |
| 9 : 12 | 3 : 4 |
| 2.5 : 5 | 1 : 2 |
Solving a proportion:
| Proportion | Missing value |
|---|---|
| 3 : 4 = 9 : ? | 12 |
| 2 : 5 = 6 : ? | 15 |
| 5 : 2 = 20 : ? | 8 |
FAQ
How do you simplify a ratio?
Divide both parts by their greatest common divisor. For 12 : 8 the GCD is 4, so it simplifies to 3 : 2.
How do you solve a proportion?
In a : b = c : ?, the missing value is (b x c) / a. For 3 : 4 = 9 : ?, that is
(4 x 9) / 3 = 12.
Can it simplify ratios with decimals?
Yes. It scales the decimals to whole numbers first, so 2.5 : 5 becomes 1 : 2.
What is a ratio?
A ratio compares two quantities, like 3 : 2. It is closely related to fractions, and equal ratios form a proportion.