Dilution Calculator
Solve for any variable in C₁V₁ = C₂V₂. Plan serial dilutions and watch the flask levels and concentration colors update as you type.
Live Reaction & Flask Simulation
Step-by-Step Bench Protocol
Pipette Stock Aliquot
Draw 10 mL of stock (10 mM) with a pipette.
Add Diluent / Buffer
Add 40 mL of water or buffer to reach the final mark.
Invert and Mix
Invert the tube to mix. You now have 50 mL at 2 mM (a 5× dilution).
Multi-Step Serial Dilution Simulator
Plan standard curves, ELISA plates, MIC tests and colony counts. Each tube shows its own color.
| Tube # | Transfer Vol | Diluent Vol | Total Vol | Dilution Factor | Final Concentration |
|---|
Precision Dilution Subtools & Calculators
Explore purpose-built calculators for stock solutions, serial dilutions, molarity conversions, cell suspensions, and industrial formulations.
C₁V₁ = C₂V₂ Calculator
Solve for any one of the four values. Type the other three.
Stock Volume Calculator
Find how much stock to use. Then top up to the final mark.
Final Concentration Calculator
Find the strength after you dilute. Enter stock and volumes.
Initial Concentration Calculator
Find the stock strength you need. Work back from the target.
Final Volume Calculator
Find the total volume that hits your target. Use what stock you have.
Diluent Volume Calculator
Find how much water or buffer to add. Volumes are taken to add up.
Make-to-Volume Calculator
Find the stock to add, then fill to a set final volume. Good for flasks with a fill line.
Fixed Diluent Volume Calculator
Find the stock to add to a set amount of diluent. Use it when the buffer is pre-filled.
Need a specific buffer, serial or industrial calculator?
Explore our complete catalog categorized by molecular biology, wet lab, chemistry, and disinfection.
How CalculatorDilution.com Works
Every result comes from the conservation-of-solute equation C₁V₁ = C₂V₂. Units are converted for you behind the scenes, so you can enter values exactly as they appear on your stock bottle and protocol.
Choose the unknown
Pick which of the four variables to solve for: stock concentration (C₁), aliquot volume (V₁), final concentration (C₂) or final volume (V₂).
Enter what you know
Type the three known values and select their units. Molar (M, mM, µM, nM), mass (mg/mL, µg/mL), percent and fold units are all supported.
Read the result instantly
The missing value, dilution factor and diluent volume (V₂ − V₁) update as you type, and the flask visualization shows the resulting color intensity.
Copy the bench protocol
Copy the generated three-step protocol into your lab notebook, or switch to the serial dilution simulator to plan a full standard curve tube by tube.
Precision Dilution Engineering & Theory
Master the fundamental principles of volumetric preparation, conservation of mass, and serial dilution across biomedical research and analytical laboratories.
The Dilution Equation
Based on the law of conservation of mass: the amount of solute in the initial aliquot equals the total solute in the final mixed volume:
- C₁: Initial / Stock concentration
- V₁: Aliquot volume drawn
- C₂: Final target concentration
- V₂: Final combined total volume
Dilution Factor & Solvent
The dilution factor expresses how many times less concentrated the new solution is compared to the stock.
Solvent Volume Required:
Always measure solute aliquot first, then bring up (Q.S.) to target volume using solvent to ensure meniscus accuracy.
Serial Dilution Standards
Used when the required concentration is orders of magnitude lower than stock, preventing pipetting errors from sub-microliter volumes:
- Minimizes pipetting error (< 1% CV)
- Essential for standard curves in qPCR & ELISA
- Determines minimum inhibitory concentrations (MIC)
- Facilitates microbial colony count plating
Bench Precision & Safety Rules
Dilution Calculator FAQ
Quick answers about C1V1 = C2V2, dilution factors, units and serial dilutions.
How do I use the C1V1 = C2V2 formula?
Multiply the stock concentration (C₁) by the volume you take from it (V₁); that product equals the final concentration (C₂) times the final volume (V₂). Rearrange to solve for the unknown, for example V₁ = (C₂ × V₂) / C₁. To make 50 mL of 2 mM solution from a 10 mM stock, you need (2 × 50) / 10 = 10 mL of stock topped up to 50 mL.
What is a dilution factor and how is it calculated?
The dilution factor (DF) tells you how many times weaker the final solution is than the stock. It equals C₁ / C₂, or equivalently V₂ / V₁. A 1:10 dilution has a DF of 10, meaning one part stock in ten parts total volume.
How much water or buffer do I add?
Subtract the aliquot volume from the final volume: V_diluent = V₂ − V₁. The calculator shows this as the solvent volume. In practice, add the stock first and then bring the solution up to the final mark (Q.S.), because some liquids contract when mixed.
Can I use different units for the stock and final concentration?
Yes, within the same family of units. Molar units (M, mM, µM, nM) convert into each other, and mass units (mg/mL, µg/mL) convert into each other. Converting between molar and mass concentration requires the compound's molecular weight, so keep C₁ and C₂ in the same family, or convert first.
How do I perform a serial dilution?
Fill each tube with diluent, transfer a fixed volume from the stock into the first tube, mix, and then transfer the same volume from each tube into the next. With a transfer of 100 µL into 900 µL of diluent, each step is a 1:10 dilution, so the concentration after n tubes is C₀ / 10ⁿ. The serial dilution simulator calculates every tube for you.
Why should I add acid to water and not the other way around?
Diluting a concentrated acid releases a lot of heat. Adding acid slowly to a larger volume of water lets that heat dissipate safely, while adding water to acid can boil locally and spatter. Always wear eye protection and follow your laboratory's safety data sheets.
Is the dilution calculator free, and is my data stored?
The calculator is completely free and needs no account. All calculations run in your browser, so the concentrations and volumes you enter are never sent to or stored on a server.