Serial Dilution Calculator
Plan equal-factor dilution steps and see the concentration, transfer volume, and diluent needed at every stage.
01 Set up your calculation
- Enter the starting concentration and the dilution factor used at each step.
- Choose up to 20 steps and the volume prepared in each tube before the next transfer.
- Transfer the calculated aliquot from stock into tube 1, then from each mixed tube into the next.
02 The relationship
For the assumptions behind these results, read the explanation below. You can also explore Dilution Factor and Solution Dilution.
Follow the numbers
For four tenfold steps starting at 1 mol/L, concentrations are 0.1, 0.01, 0.001, and 0.0001 mol/L. Preparing 10 mL per tube requires a 1 mL transfer and 9 mL diluent each time. Intermediate tubes retain 9 mL after the next transfer.
03 Small factors multiply into a large dilution
A serial dilution applies a sequence of concentration reductions. The factor for each step multiplies the previous factors, so four tenfold steps give an overall factor of ten thousand. The concentrations form a geometric sequence rather than decreasing by a fixed subtraction.
Each new tube must be mixed appropriately before taking the next aliquot. An unrepresentative aliquot breaks the assumption that the transferred material has the concentration calculated for the previous tube.
04 Prepared volume versus remaining volume
The volume input is the amount in each tube immediately after dilution. Taking an aliquot onward reduces the amount remaining in every intermediate tube. The final tube is not sampled onward in this plan, so it retains the full prepared volume.
Transfer uncertainty and contamination can propagate through successive steps. The calculator supplies an ideal quantity plan, not a quantified uncertainty analysis. Very small aliquots, adsorption, precipitation, and losses can make the actual final concentration differ from the arithmetic prediction.
Questions from the notebook
Are dilution steps counted from the stock?
Yes. Step 1 is the first diluted tube; the undiluted stock is not counted as a step.
How much stock is consumed?
This equal-volume plan consumes one transfer aliquot from the original stock to prepare tube 1.
Can factors differ between steps?
This tool uses the same factor at every step. For unequal factors, calculate each step separately and multiply the factors.
References & reading
- OpenStax, Rice University — Molarity ↗
Defines molarity and derives the dilution balance from conservation of solute.
- NIST — Guide to SI conversion factors ↗
Supports physical unit conversions. Input values are converted to the formula’s base units before calculation.
Our explanations are written for ChemistryCalc. Read how we build and check our tools. These calculations are educational estimates where the underlying model requires assumptions.