Stock Solution Dilution Series Calculator
Preparing a series of working concentrations from a stock solution is a routine lab task. This calculator uses the dilution equation C1V1 = C2V2 to generate a complete serial dilution table. Enter the stock concentration, the final volume of each dilution step, the dilution factor, and the number of steps. The table shows the concentration, volume to transfer from the previous step, and volume of diluent to add at each step. The first step always dilutes directly from the stock solution.
| Step | Concentration | Transfer from prev. (mL) | Diluent (mL) |
|---|
Dilution formulas
C1 * V1 = C2 * V2
V1 (transfer volume) = C2 * V2 / C1
Diluent volume = V2 - V1
Where C1 is the concentration of the source solution, V1 is the volume of source to transfer, C2 is the target concentration, and V2 is the total final volume. In a serial dilution, C1 for each step is the concentration of the previous step.
When to use serial vs direct dilution
- Serial dilution: more efficient when many steps are needed; small transfer volumes are required; however, errors compound across steps.
- Direct dilution from stock: more accurate for fewer steps because each dilution is independent; but impractical for very low final concentrations due to tiny transfer volumes.
- For drug dose-response curves, serial dilution is standard (e.g., 3-fold or 10-fold series across 8 to 12 concentrations).
Stock solution dilution: frequently asked questions
What is the C1V1 = C2V2 dilution formula?
C1V1 = C2V2 states that the amount of solute is conserved during dilution: initial concentration (C1) multiplied by initial volume (V1) equals the final concentration (C2) multiplied by the final volume (V2). Rearranging: V1 = C2 * V2 / C1.
What is the difference between a dilution series and a serial dilution?
In a dilution series, each step dilutes from the original stock. In a serial dilution, each step dilutes from the previous step's solution. This calculator handles both. A serial dilution is more efficient when many dilution steps are needed.
How do I prepare a 1 mM working solution from a 100 mM stock?
Using C1V1 = C2V2: V1 = (1 mM * 10 mL) / 100 mM = 0.1 mL. Add 0.1 mL of the 100 mM stock to 9.9 mL of diluent to make 10 mL of 1 mM working solution.
What units can I use for concentration?
The C1V1 = C2V2 formula works with any consistent concentration unit (mM, uM, nM, mg/mL, ug/mL, %). Ensure both C1 and C2 are in the same units, and V1 and V2 are in the same units. The output volumes will be in the same unit as V2.
How many dilution steps can this calculator generate?
This calculator generates up to 10 steps in a serial dilution series from a single stock. For each step you see the target concentration, volume to transfer from the previous step, and volume of diluent to add.
Official sources
- NIST, dilution calculations and standard solutions: NIST Guidelines for Preparation of Standards.
- CDC laboratory procedures, dilution methods: CDC Laboratory Methods.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.