1. Home
  2. Rule Of Three Calculator

Rule of Three Calculator

X

Our rule of three calculator is an online tool that facilitates solving direct and inverse proportionality problems. This type of calculation is essential in various areas such as mathematics, economics, physics, and everyday life. The rule of three allows you to determine an unknown value from three known values that maintain a proportional relationship. Our application is designed to offer you accurate results instantly. In this article, we explain how the rule of three works, how to apply it, and how our platform can simplify your life.

What is the rule of three?

The rule of three is a mathematical rule that allows solving problems based on proportionality. Through the rule of three, you can obtain an unknown number based on the proportion that exists between two numbers you do know and a third number from which you want to derive the proportional relationship. It is a fundamental tool both in the academic field and in practical everyday situations.

There are two main types of rule of three:

  • Direct Rule of Three: Used when magnitudes grow or decrease proportionally. For example, if 2 apples cost 4 dollars, how much will 5 apples cost?
  • Inverse Rule of Three: Applied when one magnitude increases while the other decreases. For example, if 4 workers complete a task in 6 hours, how long will 2 workers take?

How does the calculator work?

Calculating the rule of three is quite simple and with the help of our online calculator, you can get the result in a matter of seconds.

Direct rule of three:

  • Enter the first two values that maintain a proportional relationship (A and B).
  • Enter the third value (C) from which you want to know the proportional relationship.

If 3kg of apples cost 6 dollars, how much will 7kg of apples cost?

3
6
=
7
X
→ X =
6 x 7
3
= $14

Inverse rule of three:

  • Enter the first two values that maintain a proportional relationship (A and B).
  • Enter the third value (C) from which you want to know the inversely proportional relationship.

If 4 workers complete a task in 6 hours, how long will 2 workers take?

4
6
=
2
X
→ X =
4 x 6
2
= 12 hours

Discover the advantages of our calculator

Our application to calculate the rule of three is designed to make your life easier. Why choose our tool?

  • Easy to use: Designed with an intuitive interface so anyone can use it without complications.
  • Immediate results: Forget about manual calculations, our application does all the work for you.
  • Compatible with all devices: Access from your mobile, tablet, or computer.
  • Guaranteed precision: Performs calculations with no margin of error, ideal for students, professionals, and everyday tasks.
  • Free: Our calculator is completely free and accessible online.

Use Cases of the Rule of Three

The rule of three is useful in a wide variety of situations. Below, we show you some examples where you can apply this tool:

  • Economics: Calculate product prices based on percentage discounts or increases.
  • Physics: Solve problems related to speed, distance, and time.
  • Work: Determine work time or necessary resources based on production rates.
  • Daily life: Proportions in recipes, mixing ingredients, and more.