# Dilution factor and serial dilutions calculators

## Diluting is a process of decreasing the concentration of a solute in a solution. Dilutions and serial dilutions are a common technique used in the analysis of solutions.

The dilution factor is a measure of how much of the original solution is present in the final solution after dilution. The dilution factor calculator gives the dilutant factor as a ratio. There are two forms of the dilution factor: the ratio of the volume of dilutant to the initial solution, and the ratio of the total volume to the initial volume.

For example, if the initial volume is 10 ml, and after the dilutant has been added it is 100ml, the ratio of dilutant : original solution is 90 : 10, or 9:1. With this definition, the dilutant factor is 9. The ratio of the total (final) : original solution is 100 : 10, or 10:1. With this definition, the dilutant factor is 10.

A serial dilution is a stepwise dilution of a solution repeated a number of times. At each step, the concentration decreases. The serial dilution calculator gives the minimum volume to be left for each dilution, the starting solution volume required and the volume needed to be moved at each step for the repeat solutions.

For example, with a volume per use of 2 cm³, a percentage error (or pipette error) of 10% and 5 uses per dilution, the minimum volume required to be left for each dilution is 11 cm³. With a dilution factor of 3, the starting volume of the solution needed is 16.5 cm³ and the volume to be moved at each step for the repeat solutions is 5.5 cm³.