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Dilution Calculator – C1V1 = C2V2 Solution Dilution Tool

Quickly calculate solution dilutions with our free dilution calculator. Using the C1V1 = C2V2 formula, find any unknown concentration or volume in seconds. Perfect for lab preparation, microbiology, and chemistry experiments.

What is the Dilution Formula?

The dilution formula C1V1 = C2V2 calculates how to prepare a diluted solution from a concentrated stock. This equation states that the amount of solute remains constant before and after dilution.

Dilution Formula

C₁V₁ = C₂V₂

Where:

  • C₁ = Initial concentration (stock solution)
  • V₁ = Initial volume (volume of stock to use)
  • C₂ = Final concentration (desired concentration)
  • V₂ = Final volume (total volume after dilution)

Dilution Factor

The dilution factor equals V2/V1 or C1/C2. A 1:10 dilution means you dilute the stock 10 times. For example, mixing 1 mL of stock with 9 mL of solvent gives a total volume of 10 mL, which is a 1:10 dilution.

DilutionStock VolumeDiluent VolumeTotal VolumeDilution Factor
1:21 mL1 mL2 mL2
1:51 mL4 mL5 mL5
1:101 mL9 mL10 mL10
1:1000.1 mL9.9 mL10 mL100
1:10000.01 mL9.99 mL10 mL1000

Example Calculation

You need 100 mL of 0.1 M NaCl from a 1.0 M stock. Use C1V1 = C2V2: (1.0 M)(V1) = (0.1 M)(100 mL). Solve for V1: V1 = 10 mL. Take 10 mL of 1.0 M stock and add water to reach 100 mL total.

Concentration vs Volume Graph
How concentration changes as you add more diluent

Enter values and calculate to see the graph

Serial Dilution Examples
TubeDilutionCumulative DilutionConcentration (from 1M)
11:1010⁻¹0.1 M
21:1010⁻²0.01 M
31:1010⁻³0.001 M
41:1010⁻⁴0.0001 M
51:1010⁻⁵0.00001 M
Dilution Applications
  • Preparing standard solutions for calibration curves
  • Serial dilutions for microbiology plate counts
  • ELISA and immunoassay sample preparation
  • PCR reaction setup with diluted primers
  • Drug concentration preparation in pharmacology
  • Environmental sample analysis
How to Use This Dilution Calculator
1

Select what you want to find

Choose from the dropdown: Final Concentration (C2), Initial Volume (V1), Initial Concentration (C1), or Final Volume (V2).

2

Enter the known values

Fill in the three known values. For example, to find C2, enter C1 (stock concentration), V1 (volume of stock), and V2 (final total volume).

3

Calculate and review results

Click Calculate to get your answer. The graph shows how concentration changes with volume. Use the reference tables for common dilution ratios.

Frequently Asked Questions

What is the dilution formula?

The dilution formula is C1V1 = C2V2. This means the initial concentration times initial volume equals final concentration times final volume. The amount of solute stays constant — you're just adding more solvent.

How do I calculate dilution factor?

Dilution factor equals V2/V1 or C1/C2. A 1:10 dilution has a dilution factor of 10. If you mix 1 mL stock with 9 mL water, total volume is 10 mL, so dilution factor is 10/1 = 10.

What is a serial dilution?

Serial dilution means performing multiple dilutions in sequence. Take 1 mL from tube 1, add to 9 mL in tube 2 (1:10). Take 1 mL from tube 2, add to 9 mL in tube 3 (1:100 cumulative). This creates a concentration series for standard curves.

Do units matter for dilution calculations?

Yes, but only for consistency. C1 and C2 must use the same units (both M, both mM, etc.). V1 and V2 must use the same units (both mL, both L, etc.). The formula works with any concentration and volume units as long as they match.

How do I make a 1:100 dilution?

For a 1:100 dilution, mix 1 part stock with 99 parts diluent. For 10 mL total: add 0.1 mL (100 uL) stock to 9.9 mL diluent. For 100 mL total: add 1 mL stock to 99 mL diluent.