Drug Dilution Calculator

Calculate drug dilution ratios and volumes using the C1V1=C2V2 formula for pharmaceutical and laboratory preparation

Concentration of your stock solution

Volume of stock solution needed (calculated)

Desired final concentration

Total volume of final solution needed

Results

Stock Volume Needed (V1)

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Solvent Volume to Add

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Dilution Factor

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Frequently Asked Questions

What is the C1V1 = C2V2 formula used for?

This dilution formula calculates the volumes and concentrations needed when diluting solutions. C1 and V1 represent the initial concentration and volume, while C2 and V2 represent the final concentration and volume.

How do I calculate how much stock solution I need?

Enter your stock concentration (C1), desired final concentration (C2), and final volume (V2). The calculator will determine the volume of stock solution needed (V1) using the formula V1 = (C2 × V2) ÷ C1.

What units can I use for drug concentrations?

The calculator supports various concentration units including mg/mL, μg/mL, g/mL, and molar units (mM, μM, nM). Make sure both C1 and C2 use the same type of units for accurate calculations.

How much solvent do I need to add?

The solvent volume equals the final volume minus the stock volume (V2 - V1). This is the amount of diluent (usually water or buffer) you need to add to reach your desired final volume.

What is a dilution factor and how is it calculated?

The dilution factor shows how much the original solution is diluted. It's calculated as the initial concentration divided by the final concentration (C1/C2). A 10:1 dilution factor means the solution is 10 times more dilute.

Can I use this calculator for serial dilutions?

Yes, you can use this calculator for each step of a serial dilution. For each subsequent dilution, use the previous dilution's final concentration as the new C1 value.

What should I do if I need a very small volume of stock solution?

If the calculated stock volume is too small to measure accurately (less than 1 μL), consider making a larger final volume or creating an intermediate dilution first to make the volumes more manageable.

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