Serial Dilution Calculator

Calculate concentration at each step of a serial dilution. Enter starting concentration, dilution factor, and number of steps. Shows a dilution table and concentration chart. Arithmetic only — not medical, laboratory, or clinical advice.

e.g. 10 = 1:10 per step

Understanding Serial Dilution Math

The Serial Dilution Formula

At each step, the concentration is reduced by the dilution factor. After n steps:

C_n = C_0 ÷ (dilution factor ^ n)

A dilution factor of 10 at step 3 means the concentration is 1/1,000 of the starting value (10^3 = 1,000).

Common Dilution Factors

FactorAfter 1 stepAfter 3 stepsAfter 5 steps
1:21/21/81/32
1:51/51/1251/3,125
1:101/101/1,0001/100,000
1:1001/1001/1,000,0001/10,000,000,000

Frequently Asked Questions

1What is serial dilution?

Serial dilution is the process of repeatedly diluting a solution by a fixed factor at each step. Each step reduces the concentration by the dilution factor.

2How do I calculate concentration after serial dilution?

Multiply the starting concentration by (1 / dilution factor) for each step. After n steps: C_n = C_0 / (dilution factor ^ n).

3What is dilution factor?

The dilution factor is the ratio by which the concentration decreases at each step. A factor of 10 means each step is 1/10 the previous concentration.

4What is the difference between serial dilution and single dilution?

A single dilution applies one dilution step. Serial dilution applies the same dilution factor repeatedly across multiple steps to achieve very low concentrations.

Arithmetic dilution calculator only. Not medical, pharmaceutical, or laboratory advice.

Supplies for Reconstitution Work

The measurements on this page assume standard lab consumables. These are the generic supply categories the math above refers to.

  • Bacteriostatic water

    Multi-dose diluent; the volume you enter as diluent above.

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  • U-100 insulin syringes

    The 100-unit-per-mL scale this calculator converts to. Sold in 0.3 / 0.5 / 1 mL barrels.

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  • Alcohol prep pads

    Standard septum and surface wipes.

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  • Sterile vials

    Empty stoppered vials for reconstituted solution.

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  • Sharps container

    Required for compliant disposal of used needles.

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As an Amazon Associate I earn from qualifying purchases. These are general lab and medical consumables listed for convenience — this site provides arithmetic only and does not offer medical advice, product endorsement, or guidance on the use of any substance.

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