Restaurant, travel, rentals…

Split bills without hassle

Organize group expenses with the agility of a spreadsheet.

Rule of Three Calculator

Calculate unknown values using direct or inverse proportion

Relationship type

Value A

Value B

Value C

About

Use the Rule of Three Calculator for proportion problems.

What is the Rule of Three?

The Rule of Three is a method for solving proportion equations with one unknown value. It is commonly used in pricing, recipes, scaling measurements, and percentage-style comparisons.

Direct and inverse proportion

Direct proportion means values grow or shrink together. Inverse proportion means one value grows while the other decreases. This tool supports both modes.

When to use it

Find total price from a known unit relationship.
Scale ingredient quantities up or down.
Estimate quantities under inverse-rate conditions.

We got more utilities for you...

Generators in a dashboard

Select several utilities and put them in a dashboard.