What is calculated
Required stock volume from C1V1 = C2V2, after concentration and volume units are normalized.
Dilution Calculator
Use the Dilution Calculator to calculate and interpret required stock volume.
Required stock volume
Enter your values, then calculate to see a verified result.
Reference range
How this result is calculated
A clear calculation path based on your inputs.
Inputs usedReview the information used for this result.
Full calculation and sourcesReview the equation, normalized inputs, assumptions, and version.
Versioned calculationFormula v1.0.1
What the diluent figure means
Final volume minus stock volume is shown as an approximate arithmetic difference, not as a laboratory preparation procedure.
Important boundary
The stock concentration must be at least as high as the target concentration and both values must use the same concentration basis.
Normalize the entriesKeep both concentrations on the same basis and convert final volume to liters internally.
Substitute into C1V1 = C2V2V1 = (C2 × V2) ÷ C1
Read the stock volumeThe normalized liter result is converted to milliliters for the primary answer.
Interpretation
is the calculated stock-solution volume for the entered final concentration and final solution volume.
The displayed diluent amount is only final volume minus stock volume; actual preparation methods can require bringing the solution to a final volume.
This arithmetic does not supply chemical compatibility, safety, mixing-order, or laboratory-procedure guidance.
Use this result
Continue with your result
Compare, save, or take the next step
Did we solve your problem?Your feedback helps us improve this calculator.
Report a calculation issue Dilution Calculator: purpose and method
Calculates required stock volume and approximate diluent volume from stock concentration, target concentration, and final solution volume with visible method, validation, precision, and limitations.
Keep exploring
Related calculators and resources
Method and test recordFormula v1.0.1
- Recorded scope
- formula, units, validation, and calculator workflow
- Publisher
- CalculatorGeek
- Reviewed by
- CalculatorGeek Editorial Team
- Recorded review date
- Next source review
- Definition fixtures
- 4 configured scenarios
- Published examples
- 2 shown below
Recorded method
Formula identities, unit-equivalent inputs, invalid boundaries, and published fixtures are checked before release.
These records describe the published model and reference tests. A test-case count is not a certification of every possible input or an independent specialist review. Editorial policy
Known limitations
- Use the same chemical substance and stated concentration convention throughout the calculation.
- Round only after unit conversion and formula evaluation.
- Approximate diluent volume is final volume minus stock volume; it is not a preparation procedure or an assumption that volumes are exactly additive.
- Chemical compatibility, safety and mixing order are outside this arithmetic model.
Method sources
Latest model update
2026-10-15 - Added a context-preserving result receipt and explicit diluent, compatibility and procedure limitations without changing C1V1 = C2V2 arithmetic.
Reference inputs and expected results
These published examples are separate from the configured definition fixtures and any additional automated assertions. Expected values use the stated output units; invalid inputs are intended to be rejected.
| Case | Inputs | Expected result |
|---|---|---|
| Tenfold dilution | stock_concentration: 1 mol/L; target_concentration: 0.1 mol/L; final_volume: 1 L | stock_volume_ml: 100 |
| Milliliter final volume | stock_concentration: 2 mol/L; target_concentration: 0.5 mol/L; final_volume: 250 mL | stock_volume_ml: 62.5 |
Report an issue with this tool. Include the page URL, units, expected answer, and steps to reproduce. Do not include sensitive personal information.
On this page
Direct answer
Calculates required stock volume and approximate diluent volume from stock concentration, target concentration, and final solution volume with visible method, validation, precision, and limitations.
Continue with the Calculate required solute mass when that calculation is the next step.
How to use the calculator
- Enter the stock concentration and choose its unit.
- Enter the lower target concentration on the same chemical and concentration basis.
- Enter the intended final solution volume and its unit.
- Calculate, then review the substituted equation, required stock volume, dilution factor, and approximate arithmetic difference.
The model converts compatible units before applying C1V1 = C2V2. It does not provide a mixing order or chemical-safety procedure.
To compare this result with another relevant method, open the Molarity Calculator and verify the concentration from amount of substance and solution volume.
Formula and methodology
The conservation relationship is C1V1 = C2V2, rearranged as V1 = (C2 × V2) ÷ C1. C1 is the stock concentration, C2 is the target concentration, V2 is the intended final solution volume, and V1 is the required stock volume.
For 2 mol/L stock, a 0.2 mol/L target, and 250 mL final volume: V1 = (0.2 mol/L × 250 mL) ÷ 2 mol/L = 25 mL. The dilution factor is C1 ÷ C2 = 10.
Inputs are validated and normalized before calculation. Working precision is retained until the visible output rule is applied.
Worked example
Tenfold dilution: Stock concentration: 1 mol/L; Target concentration: 0.1 mol/L; Final solution volume: 1 L. The expected result is Required stock volume: 100 mL.
Interpretation and limitations
- Use the same chemical substance and stated concentration convention throughout the calculation.
- Round only after unit conversion and formula evaluation.
- Keep the stated units, assumptions, and population or jurisdiction with the result.
- Do not use a rounded display value as an exact input to another calculation.
Inputs, outputs and result meaning
Calculates required stock volume and approximate diluent volume from stock concentration, target concentration, and final solution volume with visible method, validation, precision, and limitations.
Inputs
- Stock concentration
- Enter the initial stock concentration. Supported units include moles per liter (mol/L) and millimoles per liter (mmol/L). The supported range is 0.000000001 through 1,000,000.
- Target concentration
- Enter the desired final concentration. Supported units include moles per liter (mol/L) and millimoles per liter (mmol/L). The supported range is 0.000000001 through 1,000,000.
- Final solution volume
- Enter the desired final prepared-solution volume. Supported units include liters (L), milliliters (mL), and microliters (uL). The supported range is 0.000000001 through 1,000,000,000.
Outputs
- Required stock volume
- This is the primary result. It is displayed in mL. The visible value uses up to 3 decimal places according to the output rule. The same result may be available in another supported unit or display mode.
- Approximate diluent volume
- It is displayed in mL. The visible value uses up to 3 decimal places according to the output rule.
V1 = (M2 x V2) / M1. Keep the result label, unit, selected mode, and stated limitations together when sharing the answer.
Frequently asked questions
What does the Dilution Calculator calculate?
Calculates required stock volume and approximate diluent volume from stock concentration, target concentration, and final solution volume with visible method, validation, precision, and limitations.
Which formula or method does the Dilution Calculator use?
V1 = (M2 x V2) / M1.
How should I interpret the required stock volume?
Interpret required stock volume with its unit, method, assumptions, and supporting outputs.
Which inputs and units does the Dilution Calculator support?
The supported fields are Stock concentration, Target concentration, and Final solution volume. Their visible labels, choices, units, and validation guidance define the accepted input.
What limitations or edge cases affect the Dilution result?
Use the same chemical substance and stated concentration convention throughout the calculation.
Sources and transparency
The sources define the method or interpretation context. Calculator fixtures verify ordinary, boundary, and invalid-input behavior; they do not create a professional recommendation.