What is a serial dilution?

A serial dilution is a stepwise reduction of a solution's concentration. Each step dilutes the previous by the same factor, so concentration drops geometrically (e.g. 1 mg/mL → 0.1 → 0.01 → 0.001 for a 1:10 series).

What does dilution factor mean?

The dilution factor is the ratio of the final volume to the volume of the original sample transferred. A factor of 10 means 1 part sample is added to 9 parts diluent, giving a 10-fold dilution at each step.

How is the diluent volume calculated?

Diluent volume = Total tube volume − Transfer volume. Transfer volume = Total tube volume ÷ Dilution factor. These values are shown in the table for every step.

What units can I use for concentration?

You can select M (molar), mM, µM, nM, mg/mL, µg/mL, ng/mL, or %. The calculator keeps the chosen unit consistent across all steps; convert to a different unit manually if needed.

Can I use a non-integer dilution factor?

Yes. You can enter decimal factors such as 2.5 or 3.16. The calculator works for any positive number greater than 1.

What is the maximum number of steps?

Up to 20 dilution steps are supported. For very large dilution factors or many steps, concentrations below 0.001 are displayed in scientific exponential notation (e.g., 1.000e-4) to maintain precision across deep dilutions.

Dilution Series Calculator

Enter a starting concentration, dilution factor, and number of steps to instantly generate a complete serial dilution table.

Dilution Parameters

Starting Concentration

Dilution Factor

e.g. 10 = 1:10 dilution per step

Total Volume per Tube

Number of Steps: 6

Set parameters and click Calculate to generate the dilution table.

Dilution Series Table

Step	Concentration	Transfer Vol.	Diluent Vol.	Total Vol.

Concentration vs. Step (log scale)

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Summary

The Dilution Series Calculator generates a complete serial dilution table for any starting concentration, dilution factor, total tube volume, and number of steps. It shows the exact transfer volume and diluent volume needed at each step alongside the resulting concentration, making it easy to plan lab protocols accurately.

How it works

Enter the starting (stock) concentration and choose its unit.
Set the dilution factor — e.g. 10 means each step is 1:10 of the previous.
Choose the total volume you want in each tube.
Select the number of dilution steps (1–20).
Click Calculate to see the full serial dilution table with concentrations and volumes.
Use the Copy Table button to paste the results into a spreadsheet.

Use cases

Preparing standard curves for ELISA or spectrophotometry assays.
Creating dilution series for microbiology MIC (minimum inhibitory concentration) tests.
Generating drug concentration gradients for cell-based assays.
Teaching serial dilution concepts in chemistry or biology labs.
Quickly converting stock solutions to working concentrations.
Verifying pipetting volumes before running a wet lab experiment.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu