Dilution
Calculator
Solve any dilution problem instantly - enter what you know and get the answer with full working shown. Built for chemistry students, biology labs, and anyone using the C1V1 = C2V2 formula. No signup, no ads.
01How Dilution Calculations Work
When you dilute a solution, the number of moles of solute stays constant. Only the volume changes. This gives the fundamental dilution equation:
C1 is the initial concentration, V1 is the stock volume, C2 is the final concentration, and V2 is the final total volume. The equation can be rearranged to solve for any one unknown: C1 = C2V2/V1, V1 = C2V2/C1, C2 = C1V1/V2, or V2 = C1V1/C2.
For the full derivation from moles, read the dilution formula guide.
02Worked Example
Preparing 250 mL of 0.1 M NaCl from a 2.0 M stock
Given: C1 = 2.0 M, C2 = 0.1 M, V2 = 250 mL, find V1
Step 1 - Rearrange: V1 = C2 × V2 / C1
Step 2 - Substitute: V1 = (0.1 × 250) / 2.0 = 12.5 mL
Step 3 - Measure 12.5 mL of the 2.0 M stock solution, transfer to a 250 mL volumetric flask, add distilled water up to the mark, and mix thoroughly.
Result: C1V1 = 2.0 × 12.5 = 25 mmol = C2V2 = 0.1 × 250.
03Frequently Asked Questions
Q1What is the dilution formula?
The dilution formula is C1V1 = C2V2, where C1 is the initial concentration, V1 is the volume of stock solution, C2 is the final concentration, and V2 is the final total volume. It works because the amount of solute stays constant when you add solvent.
Q2What does C1V1 = C2V2 mean?
C1V1 is the amount of solute before dilution, and C2V2 is the amount of solute after dilution. During an ordinary dilution you add solvent, so volume increases and concentration decreases while the moles of solute remain the same.
Q3How do I calculate dilution factor?
Dilution factor is usually calculated as initial concentration divided by final concentration, C1/C2. It can also be calculated from volume as final volume divided by stock volume, V2/V1.
Q4What is the difference between dilution factor and dilution ratio?
A dilution factor is often written as a number, such as 10, meaning the final concentration is one tenth of the original. A dilution ratio writes the same idea as 1:10, meaning 1 part stock in 10 parts total solution.
Q5How do I prepare a serial dilution?
Prepare the first dilution by mixing a measured volume of stock with solvent, then use that diluted tube as the stock for the next tube. Repeating the same dilution factor creates a predictable series such as 1:10, 1:100, and 1:1000.
Q6What is a 1:10 dilution?
A 1:10 dilution means one part original solution in ten parts final solution. For example, to make 10 mL total you would mix 1 mL stock with 9 mL solvent.
Q7How do I convert between molarity and mg/mL?
You need the molar mass of the solute. In general, molarity equals concentration in g/L divided by molar mass in g/mol, and 1 mg/mL is the same as 1 g/L.
Q8Can I use this calculator for cell culture dilutions?
Yes, if your dilution follows the same conservation idea: the number of cells or solute amount is reduced by adding diluent. For cell counts, treat the concentration unit as cells per mL and use the dilution factor workflow.
Q9What is the difference between simple dilution and serial dilution?
Simple dilution makes one target solution directly from a stock. Serial dilution makes several solutions in sequence, where each tube is diluted from the previous tube.
Q10How do I calculate the volume of solvent to add?
First calculate the stock volume V1 using C1V1 = C2V2. Then subtract that stock volume from the final volume: solvent to add = V2 - V1.
Q11What units does this calculator support?
The calculator supports M, mM, µM, nM, mg/mL, µg/mL, percent, and ppm for concentration. It supports L, mL, and µL for volume, with automatic conversion during calculation.
Q12Is this calculator free to use?
Yes. ΔPropagator tools are free to use, with no signup, no ads, and no paywall.