A ratio compares two quantities by showing how much of one quantity there is relative to another. Ratios can be written using a colon, such as 2:3, or as a fraction.

Ratio Calculator

Q: How do you simplify a ratio?

To simplify a ratio, divide both parts by their greatest common divisor. For example, 12:18 simplifies to 2:3 because both numbers can be divided by 6.

Q: What is an equivalent ratio?

Equivalent ratios represent the same relationship. Multiplying or dividing both parts of a ratio by the same non-zero number creates an equivalent ratio.

Q: Can ratios contain decimals?

Yes. A ratio can contain decimal values. The values can often be multiplied by a common factor to convert them into whole numbers before simplifying.

Calculate, simplify, and understand the relationship between two numbers with our free Ratio Calculator.

Enter two values to find their simplified ratio, decimal ratio, and equivalent ratio.

Calculate a Ratio

Enter two positive numbers to calculate and simplify their ratio.

First Value

Second Value

How the Ratio Calculator Works

A ratio compares two quantities and shows the relationship between them. For example, a ratio of 2:3 means that for every 2 units of the first quantity, there are 3 units of the second quantity.

When the two values have a common factor, the ratio can be simplified. The calculator finds the greatest common divisor of the values and uses it to produce the simplest whole-number ratio whenever possible.

Simplified Ratio = First Value ÷ GCD : Second Value ÷ GCD

Ratio Calculator Example

Suppose there are 12 red objects and 18 blue objects. Their ratio is 12:18.

Step	Calculation	Result
Original Ratio	12 : 18	12 : 18
Greatest Common Divisor	GCD(12, 18)	6
First Part	12 ÷ 6	2
Second Part	18 ÷ 6	3
Simplified Ratio	2 : 3	2 : 3

Therefore, the simplified ratio of 12 to 18 is 2:3.

Understanding Equivalent Ratios

Equivalent ratios describe the same relationship even when their numbers are different. You can create an equivalent ratio by multiplying both parts by the same non-zero number.

Ratio	Multiplier	Equivalent Ratio
2 : 3	× 2	4 : 6
2 : 3	× 3	6 : 9
2 : 3	× 5	10 : 15

Common Uses of Ratios

Ratios are used in many everyday and mathematical situations, including:

Comparing quantities
Recipes and ingredient measurements
Maps and scale drawings
Mixing materials or solutions
Comparing financial or business figures
Understanding proportions and relationships

Frequently Asked Questions

What is a ratio?

A ratio compares two quantities by showing how much of one quantity there is relative to another. A ratio can be written as 2:3 or as a fraction.

How do you simplify a ratio?

Divide both parts of the ratio by their greatest common divisor. For example, 12:18 becomes 2:3 after dividing both values by 6.

What is an equivalent ratio?

Equivalent ratios have the same relationship between their two parts. Multiplying both parts by the same non-zero number produces an equivalent ratio.

Can ratios contain decimals?

Yes. Ratios can contain decimal values. They can often be converted into whole-number ratios by multiplying both parts by an appropriate factor.