Proportion Calculator
Solve a proportion x₁:y₁ = x₂:y₂, or scale by a constant k.
Input Data
Solve missing term or scale by k.
X1
Y1
X2
Results
Solved fourth term.
15
Scale ratio.
3
Explanatory note about the result.
正比 k=3；y₂=3×5=15
At a glance:x1/y1 = x2/y2 → y2 = y1·x2/x1 (cross-multiply). Or scale all by k. Complements ratio and percentage.
Formula
x1/y1 = x2/y2.
y2 = y1·x2/x1.
How to Use
- Enter the proportion terms or a scale k.
- The tool returns the missing value.
Case Studies
2:3 = 4:y2
y2 = 3·4/2 = 6.
FAQ
Cross-multiplication?
x1·y2 = y1·x2, then solve for the unknown.
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.