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Dilution calculator

Use C₁V₁ = C₂V₂ to find how much stock solution is needed for a target concentration and final volume.

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More inputs and assumptions

Answer

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Use C₁V₁ = C₂V₂ to find how much stock solution is needed for a target concentration and final volume.

More results
Precision and calculation record
Rounding changes displayed numbers, not the calculation. Text, fractions, matrices and CSV schedules keep their own formatting. Automatic keeps up to 12 significant digits, with money shown to cents where applicable.
Saved scenario
Save the current answer, then change an input to compare. This clears when you leave.
Formula and assumptions
Use matching concentration units and matching volume units. Bring the stock up to the stated final volume; volumes may not add exactly. This is arithmetic, not a chemical handling or medical dosing instruction.
Automatic precision shows numbers to 12 significant digits. Thousands separators such as 1,000 are accepted; use a dot for decimals.
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Use +, −, ×, ÷, parentheses and %. A percentage is divided by 100. This does not change the main tool.
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Updated 
Using Dilution calculator
Use C₁V₁ = C₂V₂ to find how much stock solution is needed for a target concentration and final volume.
Use matching concentration units and matching volume units. Bring the stock up to the stated final volume; volumes may not add exactly. This is arithmetic, not a chemical handling or medical dosing instruction.
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A worked example
Example inputs: stock concentration = 10, target concentration = 2, final solution volume = 100. Stock volume needed = 20.
Before you use the result
Use matching concentration units and matching volume units. Bring the stock up to the stated final volume; volumes may not add exactly. This is arithmetic, not a chemical handling or medical dosing instruction.
Example results for stock concentration
These examples use Target concentration: 2; Final solution volume: 100. They are reference calculations, not recommended settings.
Stock concentrationStock volume needed
540
1020
2010
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ToolOctopus. “Dilution calculator.” Updated 2026-09-26. https://tooloctopus.com/dilution-calculator.
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