Need to simplify or compare ratios? Our free Ratio Calculator makes it easy to simplify ratios, find an equivalent ratio, and calculate a missing value in a ratio. Enter your numbers and get the result instantly.
Simplify a Ratio
Enter two numbers to reduce the ratio to its simplest form.
Find a Missing Value
Use a proportion such as A : B = C : X to find the missing number.
Find an Equivalent Ratio
Enter a ratio and choose a multiplier to create an equivalent ratio.
How to Use the Ratio Calculator
Using the Ratio Calculator is simple. Choose the type of calculation you need, enter the numbers, and click the calculate button.
- Simplify Ratio: Enter two numbers to reduce a ratio to its simplest form.
- Find Missing Value: Enter three known values in a proportion to calculate the missing value.
- Equivalent Ratio: Enter a ratio and a multiplier to create an equivalent ratio.
What Is a Ratio?
A ratio shows the relationship between two or more quantities. It is commonly written using a colon, such as 2:3.
For example, if a basket contains 4 apples and 6 oranges, the ratio of apples to oranges is 4:6. This can be simplified to 2:3.
Ratios are commonly used in mathematics, cooking, maps, finance, mixtures, and everyday comparisons.
How to Simplify a Ratio
To simplify a ratio, divide both numbers by their greatest common divisor (GCD).
For example:
24:36
The GCD of 24 and 36 is 12.
24 ÷ 12 = 2
36 ÷ 12 = 3
So the simplified ratio is 2:3.
How to Find a Missing Value in a Ratio
When two ratios are equal, you can use a proportion to find an unknown value.
For example:
2:5 = 8
Using cross multiplication:
2 × X = 5 × 8
2X = 40
X = 20
Therefore, the missing value is 20.
Equivalent Ratios
Equivalent ratios have the same relationship between their numbers. You can create an equivalent ratio by multiplying or dividing both parts by the same non-zero number.
For example:
3:4
Multiplying both numbers by 2 gives:
6:8
Both ratios represent the same relationship.
Ratio Formula
For a ratio:
A
the relationship between the two quantities can also be written as:
A ÷ B
When working with proportions such as:
A = C
the missing value can be calculated using:
X = (B × C) ÷ A
Ratio Calculator Examples
Here are a few simple examples:
Example 1: Simplifying a ratio
18:24 → 3:4
Example 2: Finding a missing value
3:5 = 12 → X = 20
Example 3: Finding an equivalent ratio
4:7 × 3 → 12:21
Frequently Asked Questions
What is a ratio?
A ratio compares two or more quantities and shows how they relate to each other.
How do I simplify a ratio?
Divide both parts of the ratio by their greatest common divisor. For example, 20:30 becomes 2:3.
Can a ratio contain decimals?
Ratios can contain decimal values, but simplifying them may require converting them into whole numbers first.
What is an equivalent ratio?
An equivalent ratio has the same relationship between its quantities. For example, 2:3 and 4:6 are equivalent ratios.
What is a proportion?
A proportion is an equation showing that two ratios are equal, such as 2:3 = 4:6.
Can I use this calculator for real-life ratios?
Yes. Ratios are useful for comparing quantities in areas such as recipes, maps, mixtures, measurements and everyday calculations.
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