A dilution calculator uses the formula C1V1=C2V2 to determine how much of a concentrated solution to mix with solvent to reach a target concentration. It is used in chemistry labs, cleaning applications, food preparation, and medical settings — wherever you need to precisely weaken a solution while preserving a known amount of active ingredient.
Solve For
Quick Presets
C1V1 = C2V2
Fill in three values — the calculator solves for the fourth
Result
Step-by-Step Solution
How to Use the Dilution Calculator
The dilution calculator uses the fundamental equation C1V1=C2V2 to determine the unknown quantity when preparing diluted solutions. Whether you are diluting bleach for household cleaning, preparing a saline solution, or creating working-strength reagents from a laboratory stock, this tool gives you an instant, accurate answer.
Step 1: Choose What to Solve For
Use the "Solve for" dropdown to select which variable you want to find. Most often you will solve for V2 (the final volume your solution should reach after adding solvent) or V1 (how much stock solution to measure out). You can also solve for either concentration if you know volumes but need to find an unknown strength.
Step 2: Select a Preset or Enter Values Manually
Click any quick preset — bleach disinfectant, normal saline, stock dilution, or isopropyl alcohol — to auto-populate common starting values. Otherwise, type in C1, V1, C2, and V2 leaving the field you are solving for blank. Use the unit dropdowns next to each field to match your measurement system (%, M, ppm, mg/mL for concentration; mL, L, fl oz, cups, gallons for volume).
Step 3: Click Calculate
Press the Calculate button to instantly solve for the missing variable. The results panel shows the numeric answer along with a step-by-step algebraic derivation so you can verify the logic. You will also see the dilution ratio (the ratio of stock to final volume), the volume of solvent to add, and the dilution factor (how many times more dilute the final solution is).
Understanding Concentration Units
Percent (%) is the most common unit for household chemicals and food solutions. Molarity (M, mol/L) is standard in chemistry labs. Parts per million (ppm) is used for trace substances like water treatment chemicals. Milligrams per milliliter (mg/mL) is common in pharmaceutical and medical contexts. The C1V1=C2V2 formula works the same for all these units as long as both concentrations are expressed in the same unit.
Common Dilution Examples
Household bleach (8.25%) diluted to 0.12% for surface disinfection requires about 14.5 mL of bleach per liter of water. Laboratory HCl concentrated at 12M diluted to 1M working concentration requires taking 83.3 mL of stock and bringing the total volume to 1 liter. A 1:10 dilution means you take 1 part stock and add 9 parts solvent for a 10-fold dilution factor.
Frequently Asked Questions
Is this dilution calculator free to use?
Yes, this dilution calculator is completely free. All calculations run locally in your browser using the C1V1=C2V2 formula. No signup, no account, and no data is ever sent to a server.
Is my data private when using this tool?
Absolutely. Every calculation happens entirely in your web browser. No information you enter is transmitted to any server or stored anywhere. Your data is 100% private.
What does C1V1=C2V2 mean?
C1V1=C2V2 is the dilution equation where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume. It states that the amount of solute before dilution equals the amount after dilution, since you are only adding solvent.
Can I solve for any variable in the dilution formula?
Yes. Use the 'Solve for' dropdown to choose which variable you want to calculate — C1, V1, C2, or V2. Then fill in the other three fields and click Calculate. The tool uses algebra to rearrange C1V1=C2V2 and solve for the selected unknown.
How do I calculate how much bleach to use for disinfection?
Use the bleach dilution preset or enter the bleach concentration (e.g., 8.25% for standard household bleach) as C1, your desired disinfecting concentration as C2 (e.g., 0.1% for general surfaces), and the total volume you need as V2. The calculator tells you exactly how much bleach to measure out.
What concentration units does this calculator support?
The calculator supports percent (%), molarity (M), parts per million (ppm), and milligrams per milliliter (mg/mL). As long as both concentrations use the same unit, the C1V1=C2V2 formula applies directly. The tool keeps units consistent in its calculation.
What volume units are supported?
You can enter volumes in milliliters (mL), liters (L), fluid ounces (oz), cups, or US gallons. The calculator converts all volumes to mL internally before solving, so C1 and V1 can be in different volume units than C2 and V2.
Can I use this for lab stock solution dilutions?
Yes. Enter the stock solution concentration as C1, the volume you want to take from stock as V1, and the desired working concentration as C2. Solve for V2 to get the final volume your solution should be brought to with solvent.