AI Math SolverA proportion calculator solves equations of the form a/b = c/d. Fill in three values and the tool finds the fourth using cross-multiplication, with the work shown.
A proportion is a statement that two ratios are equal. They appear everywhere from scaling recipes to converting units and solving percent problems.
Cross-multiplication turns a/b = c/d into a × d = b × c, a simple linear equation. This single move solves for any unknown and is the engine behind every proportion problem.
A proportion states that two ratios are equal: a/b = c/d. Cross-multiply to get a × d = b × c, then solve for whichever value is unknown.
Enter the three known values and a question mark for the unknown. The calculator cross-multiplies and isolates the missing value, showing every step.