What this Ratio Calculator does

This ratio calculator helps you compare two quantities and express them in their simplest form. Ratios show the relationship between numbers, often written with a colon such as 3:4 or as a fraction.

You can also use a ratio calculator to solve proportion problems where one value is missing. This makes it useful for classroom math, real-life comparisons, and scaling problems.

Why it is useful

Ratios appear in recipes, maps, aspect ratios, business comparisons, and many other situations. A clear calculator page helps users understand the idea and get an answer faster.

How to calculate a ratio

To simplify a ratio, divide both numbers by their greatest common divisor. To solve a proportion, use cross multiplication and solve the missing value.

Step 1: Enter the numbers

Type the two values you want to compare. If you are solving a proportion, enter the known values in the correct positions.

Step 2: Simplify or solve

The calculator can reduce the ratio to its simplest form or find the missing value depending on the problem type.

Step 3: Read the output

The result may be shown as a simplified ratio, a fraction, or a missing number in the proportion.

Formula

Simplified ratio: A ÷ GCD : B ÷ GCD

Proportion: A:B = C:D

Missing value: Cross multiply and divide to isolate the unknown

Example calculation

Example: Simplify the ratio 108:84.

The greatest common divisor is 12.

108 ÷ 12 = 9 and 84 ÷ 12 = 7.

So the simplified ratio is 9:7.

Example: Solve 2:3 = 10:x.

2x = 30, so x = 15.

Common uses of Ratio Calculator

Math homework and school problems.
Recipe scaling and ingredient comparison.
Business and finance comparisons.
Aspect ratio and measurement work.

Frequently asked questions

How do I calculate a ratio?

Divide both numbers by their greatest common divisor to reduce the ratio to its simplest form.

How do I simplify a ratio?

Find the largest number that divides both values evenly and divide both numbers by it.

Can a ratio have more than two numbers?

Yes. Ratios can compare more than two values in some problems.

How do I solve a missing value in a ratio?

Use a proportion and cross multiplication to isolate the missing number.

Can I use this calculator for recipes?

Yes. Ratios are useful for scaling ingredients up or down in cooking and baking.