Solve ratio problems, find equivalent ratios, and simplify proportions instantly. Free online ratio solver.
Leave exactly one field blank (or placeholder ?) to compute its proportional value.
Compute proportion solutions using our Ratio Calculator. Ideal for scaling recipes, adjusting image dimension ratios, mapping distances, or solving mathematical equations. For division solutions, you can also use our Fraction Calculator or determine percentages using the Percentage Calculator.
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Enter three known values into the fields (A, B, C, or D) and leave the target field empty. Click the button to solve the proportion. Understand proportions and scales at Wikipedia.
A ratio is a mathematical comparison of two numbers, showing how many times one value contains another (e.g. A:B).
In a proportion A:B = C:D, the product of the extremes equals the product of the means: A * D = B * C. Therefore, if one value is missing, you can solve for it by multiplying the cross values and dividing by the remaining value.