Dilution Calculator

Calculate dilutions using the C1V1 = C2V2 formula. Enter three known values to find the fourth. Perfect for preparing lab solutions from stock concentrations.

Core Formula: C1 × V1 = C2 × V2 Where: • C1 = Initial (stock) concentration • V1 = Initial (stock) volume • C2 = Final (diluted) concentration • V2 = Final (diluted) volume Derived Formulas: C2 = (C1 × V1) ÷ V2 V2 = (C1 × V1) ÷ C2 C1 = (C2 × V2) ÷ V1 V1 = (C2 × V2) ÷ C1 Dilution Factor (DF) = V2 ÷ V1 = C1 ÷ C2 Solvent to Add = V2 - V1
Example 1 (Common Lab Dilution): Make 100 mL of 0.1 M HCl from 1 M stock C1 = 1 M, C2 = 0.1 M, V2 = 100 mL V1 = (0.1 × 100) ÷ 1 = 10 mL Take 10 mL stock, add 90 mL water Example 2 (Serial Dilution): Dilute 1 mL of 1 M solution to 10 mL (1:10) C1 = 1 M, V1 = 1 mL, V2 = 10 mL C2 = (1 × 1) ÷ 10 = 0.1 M Dilution factor = 10x Example 3 (Micro-scale): Prepare 500 µL of 10 µM from 1 mM stock C1 = 1 mM = 1000 µM, C2 = 10 µM, V2 = 500 µL V1 = (10 × 500) ÷ 1000 = 5 µL Add 5 µL stock to 495 µL solvent Example 4 (Percent Solutions): Make 250 mL of 5% from 20% stock solution C1 = 20%, C2 = 5%, V2 = 250 mL V1 = (5 × 250) ÷ 20 = 62.5 mL Use 62.5 mL stock + 187.5 mL water

What is the dilution formula C1V1 = C2V2?

C1V1 = C2V2 relates the initial concentration (C1) and volume (V1) to the final concentration (C2) and volume (V2). This formula works because the number of moles of solute remains constant during dilution - you are only adding more solvent.

How do I dilute a stock solution?

Calculate the volume needed using V1 = (C2 × V2) ÷ C1. Measure this volume of stock solution, then add solvent to reach the final volume V2. For example, to make 100 mL of 0.1 M from 1 M stock: V1 = (0.1 × 100) ÷ 1 = 10 mL. Take 10 mL stock and add water to 100 mL total.

Can I use any concentration units?

Yes, as long as C1 and C2 use the same units (both M, both g/L, both %, etc.). The volumes V1 and V2 must also use the same units (both mL, both L, etc.). The calculator handles conversions automatically.

What is a serial dilution?

A serial dilution is a stepwise dilution of a solution, using the diluted solution from one step as the stock for the next. Common in microbiology (e.g., 10-fold dilutions: 1:10, 1:100, 1:1000). Use C1V1 = C2V2 for each step.

How much solvent do I add?

Volume of solvent to add = V2 - V1. This is the final volume minus the initial volume. For example, if V1 = 10 mL and V2 = 100 mL, add 90 mL of solvent to the 10 mL stock solution.

What is the dilution factor?

Dilution factor (DF) = V2 ÷ V1 = C1 ÷ C2. A 10-fold dilution means DF = 10. For example, diluting 10 mL to 100 mL gives DF = 10. The final concentration is 1/10 of the original.

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