METHOD
How it is calculated
Direct: x=B×C/A. Inverse: x=A×B/C.
∑ Math and geometry
Rule of three calculator
Find the fourth value in a direct or inverse proportion.
01
Your inputs
Starting values are an example. Replace them with your own.
Your inputs stay in your browser.
02
Your result
Enter your details and run the calculation.
TRACEABLE
Sources and validity
Basic arithmetic or geometry using the formula shown. Uses only your inputs.
How we maintain data ↗