Serial Dilution Factor Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/4/2026
The total dilution factor of a series of successive dilutions is calculated by multiplying together the factors of each step. For three successive tenfold dilutions (a factor of 10 each), the total dilution factor is 1000, a final dilution of one in a thousand.
Explanation
Our dilution calculator calculates the volume of stock solution to draw for a SINGLE dilution, from the conservation of the amount of substance (C1×V1=C2×V2). This calculator goes further: it combines the dilution factors of several successive steps — a very common lab technique called serial dilution, used in microbiology to count bacterial colonies, or to prepare a range of concentrations for a calibration curve. The principle is exactly the same as our molar concentration calculator: each dilution step applies to the solution already diluted by the previous step, never directly to the starting solution, which makes the total dilution factor MULTIPLICATIVE, not additive. For example, a tenfold dilution followed by a second tenfold dilution doesn't give a twentyfold dilution (10+10), but a hundredfold dilution (10×10=100): each step divides the concentration, already reduced by the previous step, by 10 again. It's this multiplicative property that lets just a few tenfold dilution steps reach enormous dilution factors (a million with 6 steps) while only ever handling small, precise volumes at each step, rather than attempting a single extreme dilution, far harder to carry out precisely.
Example: three successive tenfold dilutions
Inputs
Step 1 factor: 10. Step 2 factor: 10. Step 3 factor: 10.
Calculation
Total dilution factor = 10 × 10 × 10 = 1000.
Result
This series of three tenfold dilutions produces a total dilution factor of 1000 (a one-in-a-thousand dilution).
Frequently asked questions
Why do dilution factors multiply rather than add together?
Because each dilution step doesn't apply to the starting concentration, but to the concentration already reduced by the previous step: dividing an already-tenfold-reduced result by 10 again amounts to dividing by 100 overall (10×10), not by 20 (10+10). It's exactly the same multiplicative logic as a multi-step chemical synthesis yield.
How do I find the final concentration from the total dilution factor?
Simply divide the stock solution's initial concentration by the total dilution factor obtained: a 1 mol/L solution subjected to a total dilution factor of 1000 will give a final concentration of 0.001 mol/L (1 mol/L ÷ 1000).
What if my series only has 2 dilutions?
Leave the third step's factor at 1: multiplying by 1 doesn't change the result, which amounts exactly to ignoring that step and only combining the first two dilution factors.