Serial Dilution Calculator Formula

Understand the math behind the serial dilution calculator. Each variable explained with a worked example.

Formulas Used

Final Concentration

final_conc = initial_conc / pow(dilution_factor, num_steps)

Total Dilution Factor

total_dilution = pow(dilution_factor, num_steps)

Variables

VariableDescriptionDefault
initial_concInitial Concentration(M)1
dilution_factorDilution Factor10
num_stepsNumber of Steps3

How It Works

How to Calculate Serial Dilution

Formula

C_final = C_initial / (DF)^n

Each step reduces concentration by the dilution factor.

Worked Example

3 serial 1:10 dilutions starting from 1 M.

initial_conc = 1dilution_factor = 10num_steps = 3
  1. 01Total dilution = 10^3 = 1000
  2. 02C_final = 1 / 1000
  3. 03C_final = 0.001 M

Frequently Asked Questions

What is a serial dilution?

A stepwise dilution where each step uses the previous dilution as the stock, allowing very large total dilutions.

What is the dilution factor?

The ratio of final volume to sample volume transferred. A 1:10 dilution has factor 10.

When are serial dilutions used?

Microbiology colony counting, antibody titers, and calibration curves.

Ready to run the numbers?

Open Serial Dilution Calculator