Dilution Factor Calculator
Calculate the dilution factor for a simple one-step dilution or a multi-step serial dilution. Enter your volumes and starting concentration to find the final concentration after dilution.
The dilution factor tells you how many times you have diluted a solution. A dilution factor of 10 means the solution is 10 times less concentrated than the original.
Simple Dilution
Dilution factor = total volume / sample volume
If you add 1 mL of stock to 9 mL of water (10 mL total), the dilution factor is 10 mL / 1 mL = 10, often written as 1:10.
Serial Dilution
In a serial dilution, each tube is diluted by the same factor, and you repeat the process multiple times. The total dilution factor is the per-step factor raised to the power of the number of steps.
Total DF = (per-step DF)^n
For example, three 1:10 dilutions give a total dilution of 10^3 = 1,000. A 1 M stock becomes 0.001 M (1 mM).
When to Use Serial Dilutions
Serial dilutions are standard in microbiology (colony counting), immunology (antibody titers), and pharmacology (dose-response curves). They let you cover a wide concentration range with consistent step sizes.