Ratio calculator
Find d so that a:b and c:d have the same ratio.
Formula
d = b × c / a
d — missing value ≈ (3)×(8)÷(2)
How to use
- Enter a and b for the known ratio.
- Enter c for the new ratio.
- Read the missing value d.
Examples
- 2:3 = 8:12.
- 5:2 = 20:8.
Frequently asked questions
Which term is calculated?
The fourth term d in a:b =c:d.
Must all values use the same unit?
Use matching units for corresponding terms a and c, and for b and d.
Does this simplify a ratio?
It solves a proportion; it does not return lowest integer terms.
Sources
Updated: