โ Math
Cross Multiply Calculator
Cross multiplication multiplies the numerator of each fraction by the denominator of the other, turning a proportion into a simple equation. It is the fastest way to find a missing term.
How it works
Numerator of first fraction
Denominator of first fraction
Numerator of second fraction
Missing value
Cross product
Ratio a รท b
Frequently asked questions
How do I use the Cross Multiply Calculator?
Fill in the fields above โ the result recalculates instantly as you type. Everything runs in your browser, so the values you enter are never collected or stored.
Is this calculator free?
Yes. It is completely free, requires no account, and works on phones, tablets and desktops.