Ratio Calculator

Need to simplify or compare ratios? This ratio calculator helps you reduce ratios to their simplest form, check if two ratios are equivalent, or find a missing value in a ratio equation.

Ratios are used in math, finance, recipes, construction, and statistics to compare two or more numbers. Instead of working them out manually, this calculator gives instant answers with step-by-step clarity.

What is a Ratio?

A ratio is a way of comparing two quantities by showing how many times one value contains or is contained within the other. For example, the ratio 2:3 means for every 2 parts of one quantity, there are 3 parts of another.

How Does the Ratio Calculator Work?

The calculator offers three main functions:

  • Simplify a ratio (e.g., 12:16 becomes 3:4)
  • Compare two ratios (e.g., check if 4:6 is equal to 10:15)
  • Find a missing value (solve a:b = c:x)

By covering simplification, comparison, and proportion solving, it works as an all-in-one tool for ratio calculations.

Ratio Calculator

This free ratio calculator simplifies ratios, compares two ratios, or finds the missing value in a ratio equation.






How to Simplify a Ratio

To simplify a ratio, divide both numbers by their greatest common divisor (GCD). For example, 12:16 can be simplified by dividing both numbers by 4, resulting in 3:4.

Original RatioDivisorSimplified Ratio
12:16÷43:4
18:24÷63:4
50:100÷501:2

How to Compare Two Ratios

Two ratios are equal if they simplify to the same value. For example, 4:6 and 10:15 are equivalent because both reduce to 2:3.

Ratio 1Ratio 2Are They Equal?
4:610:15Yes
5:715:21Yes
8:126:10No

How to Find a Missing Value in a Ratio

To solve for a missing value in a ratio equation a:b = c:x, use cross multiplication. The formula is x = (b × c) ÷ a.

EquationCalculationResult
4:6 = 10:x(6 × 10) ÷ 4x = 15
3:5 = 12:x(5 × 12) ÷ 3x = 20
7:9 = 21:x(9 × 21) ÷ 7x = 27

Common Uses of Ratios

Ratios are used in many real-world scenarios, such as:

  • Cooking – Adjusting recipe quantities (e.g., 2:1 flour to sugar)
  • Finance – Debt-to-income or profit ratios
  • Education – Student-to-teacher ratios
  • Construction – Cement-to-sand mixing ratios
  • Statistics – Probability and odds ratios

Ratio Calculator FAQs

How do you simplify a ratio?

To simplify a ratio, divide both numbers by their greatest common divisor. For example, 12:16 simplifies to 3:4.

How can I compare two ratios?

Two ratios are equal if they reduce to the same simplified form. For example, 4:6 and 10:15 are equal because both reduce to 2:3.

How do I find a missing value in a ratio?

Use cross multiplication. If a:b = c:x, then x = (b × c) ÷ a.

Where are ratios used in real life?

Ratios are used in recipes, finance, statistics, construction, and education. They help compare quantities in simple proportional terms.

What is the difference between ratio and proportion?

A ratio compares two quantities, while a proportion states that two ratios are equal.