Chemistry calculator
Dilution Calculator
Calculate concentration or volume changes with the dilution equation C1 × V1 = C2 × V2.
Calculated V2
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Enter the other three values to calculate.
What is a dilution?
A dilution lowers the concentration of a solution by adding solvent while keeping the amount of dissolved solute constant. The dilution calculator finds any one of the four values in the relationship between the starting and ending solutions.
Dilution formula
C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume. Concentrations must have the same dimensions, and volumes must have the same dimensions. This calculator converts them to M and L internally.
How to use C1V1 = C2V2
Choose the value you want to find, enter the other three values, and select each unit. The calculator converts M, mM, and µM to mol/L and µL, mL, and L to liters before rearranging the equation.
For example, 1 M × 100 mL = 0.5 M × V2, so V2 is 200 mL. The volume of solvent to add would be 100 mL if the initial 100 mL is already part of the final solution.
Worked dilution examples
To find a final concentration, use 2 M × 25 mL = C2 × 100 mL, giving C2 = 0.5 M.
For a mixed concentration-unit example, 1 M is 1,000 mM. With C2 = 100 mM and V2 = 500 mL:
Common laboratory dilution uses
Dilutions are used to prepare calibration standards, make working solutions from concentrated stocks, reduce reagent strength, prepare serial dilutions, and bring samples into the measurable range of an instrument. In practice, mix thoroughly and treat V2 as the total final solution volume.
Dilution versus molarity
Molarity calculates concentration from the amount of solute and total solution volume. Dilution calculations compare two concentrations and volumes when the solute amount stays constant. Use the molarity calculator when moles or mass are known; use this calculator when a stock and a final solution are related.
Frequently asked questions
Can I mix mM and M?
Yes. The calculator converts both to mol/L, so 1 M equals 1,000 mM and 1 mM equals 1,000 µM.
Can I mix mL and L?
Yes. µL, mL, and L are converted to liters before the calculation, and the answer is shown in the selected output unit.
What does a zero input mean?
Zero is accepted as a concentration or numerator where the equation remains defined. A zero denominator cannot produce a meaningful result, so the calculator shows a dash until a positive divisor is entered.
What is the difference between V1 and V2?
V1 is the volume of the initial stock solution being used. V2 is the total volume after dilution, including the stock and added solvent.