Proportion Solver
Solve proportions (a/b = c/d)
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Enter 3 values to find the 4th. Leave one field empty.
How to Use Proportion Solver
Enter values
Enter 3 of 4 values.
Solve
Find the missing value.
Steps
See cross-multiplication steps.
Why Choose AllTools Proportion Solver?
- ✓ Cross multiplication
- ✓ Step-by-step
- ✓ Any missing value
- ✓ Formula display
- ✓ Quick solve
- ✓ No data stored
Related Resources
Frequently Asked Questions
How does cross multiplication work? ▼
In a/b = c/d, multiply across: a×d = b×c. Then solve for the unknown.
How does cross multiplication work? ▼
For a/b = c/d, cross multiply: a*d = b*c, then solve for the unknown.
Does this work on mobile? ▼
Yes. All AllTools calculators are fully responsive and work on phones and tablets.
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