Chemistry

Dilution Calculator

Use C1V1=C2V2 to solve dilution and solution prep problems.

Formula reviewed: 2026-02-14 Chemistry

Use this free online Dilution Calculator to applies the C1V1 = C2V2 relation to find how much stock or solvent is needed for a target concentration. It is useful for classwork, lab checks, design screening, and engineering sanity checks where units and assumptions must stay visible. The form focuses on Mode, C1, V1, C2, V2 and returns Dilution Inputs, Result, so you can move from input to answer without setting up a spreadsheet or custom script. Run one realistic example, adjust the inputs, and compare how the result changes before you copy or share it. Check units and formula assumptions carefully; for safety-critical or code-governed work, validate the result with authoritative references.

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Input Pattern

Enter values in the left panel, keep units explicit, run the calculation, then copy or share the result. Invalid fields are highlighted immediately.

How to use this tool

Enter Mode, C1, V1, C2, V2 for the dilution calculator, keeping units, dates, or text format consistent with the form labels.
Choose the relevant mode, unit, or option values before running so the output answers the right version of the question.
Click "Run the tool" and review Dilution Inputs, Result for the primary output.
Verify units and assumptions, especially before using the result for design, lab, or safety-sensitive work.

Dilution Inputs

Use C1V1 = C2V2 to solve one unknown.

Result

Solved value: 0.200000

Dilution and Concentration Planning

Conserving Solute

Dilution reduces concentration by adding solvent while keeping the amount of solute the same. The common relationship C1V1 = C2V2 expresses that conservation: initial concentration times the volume taken from the stock equals final concentration times final volume.

This equation is simple because it assumes the solute amount is unchanged. If a reaction, evaporation, precipitation, adsorption, or degradation occurs, ordinary dilution math no longer describes the system. The equation applies when the operation is truly mixing and volume adjustment.

Stock Solutions

A stock solution is a concentrated solution prepared for later dilution. Stocks save time, improve consistency, and reduce weighing of tiny masses. To make a working solution, a measured volume of stock is transferred and solvent is added until the final volume is reached.

The final volume is the volume of the entire solution, not the amount of solvent added. If 10 mL of stock is diluted to 100 mL, the solvent added is approximately 90 mL, not 100 mL. This distinction matters in lab protocols and manufacturing recipes.

Serial Dilutions

Serial dilution performs repeated dilution steps, often by the same factor each time. This is useful when a very large dilution would be inaccurate or inconvenient in one step. Microbiology, analytical chemistry, pharmacology, and calibration workflows often use serial dilutions to span wide concentration ranges.

Errors can compound across steps. Pipetting precision, mixing completeness, carryover, and labeling discipline all matter. A serial dilution table should make each transfer and final volume explicit so the cumulative dilution factor is traceable.

Accuracy and Safety

Dilution accuracy depends on calibrated glassware, temperature, clean technique, and compatible units. Percent solutions, molarity, mass concentration, and ratios can all describe concentration, but they are not interchangeable without conversion.

Safety can also depend on dilution order. For strong acids, the standard rule is to add acid to water, not water to acid, because dilution can release heat. Concentration math tells you how much to mix; chemical safety tells you how to mix it.

How to interpret the result

C1 is 1.0. Compare it with the assumptions and units shown on this page before using it in a workflow.
V1 is 100.0. Compare it with the assumptions and units shown on this page before using it in a workflow.
C2 is 0.2. Compare it with the assumptions and units shown on this page before using it in a workflow.
Check concentration units, purity, measurement precision, temperature assumptions, and lab safety requirements before preparing or reporting a result.

Confidence and limitations

Outputs are deterministic formula results and depend entirely on input quality and units.
Results are for planning and learning; verify with domain standards before safety-critical use.
Assumes ideal conditions and clean stoichiometry; lab context can change real outcomes.

Formula References

Core chemistry equations such as PV=nRT, M=n/V, C1V1=C2V2, and pH definitions.
Assumes ideal solution/gas behavior unless noted.

Assumptions

Outputs are deterministic formula results and depend entirely on input quality and units.
Results are for planning and learning; verify with domain standards before safety-critical use.
Assumes ideal conditions and clean stoichiometry; lab context can change real outcomes.

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