Chemistry

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Chemistry

Molarity to Dilution Calculator.

Calculates the volume of stock solution needed to prepare a diluted solution of desired molarity and volume.

Results update live as you type.
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Your inputs

How it works

  1. 1

    Enter the stock concentration (C1) in molarity.

  2. 2

    Enter the desired final concentration (C2) in molarity.

  3. 3

    Enter the final volume (V2) you want to prepare.

  4. 4

    The calculator computes the volume of stock solution (V1) needed using C1×V1 = C2×V2.

v2 * (c2 / c1)

Frequently asked questions

What is the dilution formula?

The formula is C1×V1 = C2×V2, where C1 and V1 are the concentration and volume of the stock solution, and C2 and V2 are the concentration and volume of the final diluted solution.

How do I prepare a dilution?

Measure the calculated volume of stock solution (V1) and add it to a volumetric flask. Then add solvent (usually water) up to the final volume (V2) and mix well.

What if my stock concentration is lower than the desired concentration?

If C1 is less than C2, the formula would give a V1 greater than V2, which is impossible. You need a more concentrated stock solution or a different approach.

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Volume of stock needed (V1)

0mL

Volume of diluent to add0mL
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How it works

Calculates the volume of stock solution needed to prepare a diluted solution of desired molarity and volume.

  1. Enter the stock concentration (C1) in molarity.
  2. Enter the desired final concentration (C2) in molarity.
  3. Enter the final volume (V2) you want to prepare.
  4. The calculator computes the volume of stock solution (V1) needed using C1×V1 = C2×V2.

Formulas

The math behind this calculator, written out so you can verify the result.

Dilution equation

C1 × V1 = C2 × V2

The product of concentration and volume remains constant when diluting a solution.

Example:

Input: C1 = 1 M, C2 = 0.1 M, V2 = 100 mL

Calculation: V1 = (0.1 × 100) / 1 = 10 mL

Result: Take 10 mL of stock and add solvent to 100 mL.

Real-world use cases

Where this calculation shows up in everyday life.

Preparing standard solutions

Dilute a concentrated stock to a specific molarity for experiments.

Example: Make 500 mL of 0.2 M HCl from 2 M HCl.

Serial dilutions

Create a series of lower concentrations by successive dilutions.

Example: Dilute 1 M to 0.1 M, then 0.1 M to 0.01 M.

Buffer preparation

Adjust buffer concentration to desired molarity for assays.

Example: Dilute 10× buffer to 1× working solution.

Tips and common mistakes

Tips

  • Always add acid to water, not water to acid, when diluting strong acids.
  • Use volumetric flasks for accurate final volumes.
  • Mix thoroughly after dilution to ensure homogeneity.
  • Double-check units: ensure concentrations are in the same units (M) and volumes in the same units (mL).

Common Mistakes to Avoid

  • Using the formula incorrectly by swapping C1 and C2.
  • Forgetting to account for the volume of stock when adding solvent.
  • Assuming volumes are additive when mixing different solutions.

Assumptions and limitations

  • Use the stated inputs and units.
  • Results are estimates for planning and education.
  • Check measurements and source data before making an important decision.