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Solution Dilution Calculator

This Solution Dilution Calculator helps wet-lab users prepare a target concentration from a stock solution with the standard dilution relationship.

This Solution Dilution Calculator lets you calculate stock volume, final volume, or final concentration, then turn the result into a bench-ready protocol with unit checks and pipetting guidance.

C1V1=C2V2
Common Solution Dilution Calculator tasks
How much stock do I add?
Use Solve V1 when you know the stock concentration, target concentration, and final volume.
My stock is limited
Use Solve V2 to find the maximum volume you can make from the amount of stock you still have.
The computed volume is tiny
Check the substitution and use the 2-step dilution suggestion when the direct transfer is too small to pipette well.

Solution Dilution Calculator

Stock concentration (C1) *
Target concentration (C2) *
Final volume (V2) *
Practical pipetting (optional)
Intermediate volume

Results

Dilution equation
C1V1=C2V2
Stock volume (V1)
0.1 mL
Final volume (V2)
20 mL
Diluent volume
19.9 mL
Dilution factor
200×
Target concentration (C2)
50 µM
Preparation instructions
C1·V1 = C2·V2 C1 = 10 mM V1 = 0.1 mL C2 = 50 µM V2 = 20 mL Preparation (single-step) - Add 0.1 mL of stock to a tube - Add 19.9 mL of diluent (water/buffer) - Mix to reach total volume 20 mL Dilution factor: 200×
Substitution
V1=C2 V2C1
V1=50 µM · 20 mL10 mM=0.1 mL

Serial Dilution (quick table)

Start concentration
Final volume per tube
Dilution factor per step
Number of steps
StepConcentrationTransferDiluent
01 mM100 µL900 µL
10.1 mM100 µL900 µL
20.01 mM100 µL900 µL
30.001 mM100 µL900 µL
41.000e-4 mM100 µL900 µL
51.000e-5 mM100 µL900 µL

How to use this Solution Dilution Calculator

A practical way to use this Solution Dilution Calculator without overthinking the setup.

1

Choose a solve mode

Most cases: Solve V1. If stock is limited: Solve V2. If you mixed already: Solve C2.

2

Enter known values

Use compatible concentration units for C1 and C2 (same unit type).

3

Read volumes & factor

You’ll get stock volume, diluent volume, and dilution factor.

4

Copy protocol

Copy preparation steps into your lab notebook and execute at the bench.

What this Solution Dilution Calculator does

Dilution equation
Unit-aware
Protocol output

This Solution Dilution Calculator helps you dilute a stock solution to a target concentration and total volume. The Solution Dilution Calculator also generates copy-friendly preparation steps and a quick serial dilution table.

Dilution equation
C1V1=C2V2
The same relationship is sometimes written with M in place of concentration.
C1 — stock concentration
Concentration of the concentrated stock solution.
V1 — volume from stock
Volume removed (aliquoted) from the stock solution.
C2 — final concentration
Concentration of the diluted solution after mixing.
V2 — final solution volume
Total volume after adding diluent to reach V2.
Inputs
Stock concentration (C1), target concentration (C2), and volume (V1 or V2) depending on the mode.
Outputs
Stock volume to transfer (V1), diluent volume to add, and dilution factor.
Lab-ready
Includes a two-step suggestion when V1 is too small to pipette reliably.

Solution Dilution Calculator: Common pitfalls

Make sure C1 and C2 are the same unit type (both molar, both mass/volume, or both %).
If C2 > C1, you cannot dilute to reach the target—use a stronger stock or change the target.
If V1 is below your pipette’s reliable range, use the two-step suggestion or serial dilution.
Percent solutions and molarity are not directly interchangeable without additional information (e.g., MW, density).

Solution Dilution Calculator units and assumptions

The Solution Dilution Calculator is flexible, but the concentration terms and the volume terms must remain comparable.

01
Match concentration type
Keep concentration types matched: molarity with molarity, mass/volume with mass/volume, or percent with percent.
02
Match volume scale
Keep V1 and V2 in compatible volume units. The calculator rescales L, mL, and µL automatically.
03
Do not cross unit systems
Do not mix molarity with mg/mL unless molecular weight is known and you convert explicitly.
04
Check bench feasibility
A mathematically correct V1 can still be impractical. If it falls below your pipette range, use a 2-step dilution.

Solution Dilution Calculator examples

These Solution Dilution Calculator examples follow a textbook-style setup so you can verify the equation, substitution, and final answer before mixing the solution.

Example 1: make a 1× staining solution from a 20× stock
Given: Prepare 8 mL of a 1× working solution from a 20× stock reagent.
Formula
V1=C2V2C1
V1=1× · 8 mL20×=0.4 mL = 400 uL
Answer: Transfer 400 µL of stock and add 7.6 mL of diluent.
Lab note: This is a common bench pattern for dye, buffer additive, or supplement stocks.
Example 2: the stock is limited
Given: You have 120 µL of a 250 µM probe stock and need a 12.5 µM working solution. Solve for the maximum final volume.
Formula
V2=C1V1C2
V2=250 uM · 120 uL12.5 uM=2400 uL = 2.4 mL
Answer: You can prepare 2.4 mL total solution.
Lab note: This is useful when the reagent is expensive or the remaining stock is small.
Example 3: back-calculate the final concentration
Given: A 25 µM ROX stock contributes 2 µL into a 50 µL qPCR mix. Solve for the final concentration in the reaction.
Formula
C2=C1V1V2
C2=25 uM · 2 uL50 uL=1 uM
Answer: The final concentration in the reaction is 1 µM.
Lab note: This mode is useful for reaction components, supplements, and additives already present in a master mix.
Example 4: choose a 2-step dilution instead of forcing a tiny transfer
Given: Prepare 50 mL of a 2 nM control solution from a 200 µM stock. The direct transfer is mathematically valid but too small for routine pipetting.
Formula
V1=2 nM · 50 mL200 uM=0.5 uL
Step 1:V1=2 uM · 1 mL200 uM=10 uL
Step 2:V1=2 nM · 50 mL2 uM=50 uL
Answer: Directly, V1 is 0.5 µL. A safer workflow is: make 1 mL of a 2 µM intermediate with 10 µL stock, then use 50 µL of that intermediate for the final mix.
Lab note: When the first answer falls below your comfortable pipetting range, switch to an intermediate working stock.

Why this Solution Dilution Calculator works

Why the equation works

The dilution equation assumes the amount of solute is conserved during dilution: you add solvent, but you do not change the number of moles (or mass) of solute you transferred.

If concentration is defined as amount per volume, then amount = concentration × volume. Setting the initial amount equal to the final amount yields the dilution equation.

Units & assumptions

This relation is valid for any concentration unit as long as both sides use compatible units (e.g., both molar, or both mass/volume, or both %).

For conversions between mass concentration and molarity, you additionally need molecular weight; that is a different calculator category.

Practical notes

Practical note: volumes are additive only as an approximation for dilute aqueous solutions. For most molecular biology working solutions, the approximation is sufficient.

Solution Dilution Calculator FAQ

What do the stock and final terms mean in the dilution equation?

C1/V1 are the concentration and volume of the stock (concentrated) solution. C2/V2 are the desired concentration and final volume after dilution.

What is the dilution factor?

Dilution factor is C1/C2 (equivalently V2/V1). A 10× dilution means the final concentration is 10 times lower than the stock.

What if my target concentration is higher than my stock?

That is not a dilution. You need a more concentrated stock, concentrate the sample, or adjust your target concentration.

My calculated V1 is too small to pipette. What should I do?

Use a two-step dilution (make an intermediate solution first) or plan a serial dilution so each transfer volume is within your pipette’s reliable range.

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