Proportion Calculator

Solve a / b = c / xx = (b × c) / a

FIRST RATIO

=

SECOND RATIO

x
Unknown
Proportion formula answer: x = (4 × 6) / 3
calculated x 8.000

Proportion Calculator – Solve a/b = c/x Easily

The Proportion Calculator helps you quickly solve ratios and find the missing value in a proportional equation. In mathematics, a proportion means two ratios are equal. By using the method of cross multiplication, you can easily calculate the unknown value in the equation.

For example, if you know three numbers in a proportion like a / b = c / x, the calculator can instantly determine the missing value x.

What Is a Proportion?

A proportion is a mathematical relationship that shows two ratios are equal. It is commonly written in the form a / b = c / d, where both fractions represent the same value.

In simple terms, a proportion compares two ratios to show that they have the same relationship. Proportions are widely used in mathematics, finance, cooking recipes, engineering measurements, and many everyday calculations where values need to stay in the same ratio.

Proportion Formula

a / b = c / x

Cross multiply:

a × x = b × c
x = (b × c) / a

Step-by-Step Solution

3 / 4 = 6 / x

Step 1: 3 × x = 4 × 6

Step 2: 3x = 24

Step 3: x = 24 / 3

x = 8

Examples of Proportion Calculations

Example 1

2 / 5 = 10 / x

2x = 50

x = 25

Example 2

4 / 7 = 12 / x

4x = 84

x = 21

Example 3

5 notebooks cost $10

12 notebooks cost = ?

x = 24

Real-Life Uses of Proportions

Cooking

Adjust ingredient quantities when changing recipe servings.

Finance

Calculate proportional salary and profit.

Engineering

Scale drawings and measurements.

Education

Solve algebra and ratio problems.

FAQ on Proportion Calculator

What is a proportion in math?

A proportion is an equation showing that two ratios are equal.

How do you solve proportions?

Solve proportions using cross multiplication.

What is cross multiplication?

Cross multiplication means multiplying diagonally in a proportion equation.