Calculator
For a/b = c/d, choose the unknown and enter the other three values. The calculator uses cross multiplication.
Find
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d6
Completed proportion2 / 4 = 3 / 6
Show the steps
1. Cross multiply
a x d = b x c; 2 x 6 = 4 x 3.
2. Isolate the unknown
d = (b x c) / a = (4 x 3) / 2 = 6
Method and variables
Ratio & Proportion Calculator
Formula: a / b = c / d; a x d = b x c
Assumption: Three terms are known and the proportion can be expressed as a/b = c/d; the divisor involved in the calculation cannot be zero.
Worked example
Ratio & Proportion Calculator
For 2/4 = 3/d, cross multiply: 2d = 12, so d = 6.