One of our users asked how much it will be for 25 liters if 2 liters cost .50.
This is simple proportion, and this is simple calculator which finds unknown member of proportion. It was built for those who are lazy to do one multiplication and one division (or unsure which should be multiplied and which should be divided.
Fill three fields with numbers and leave unknown with x, and the calculator finds the x.
For example, if the unknown is bottom right, i.e. the formula is
Then, for given A, B, С, calculator finds X as