Worked example
For a 20 mg/mL stock, a 5 mg/mL target and a 100 mL final volume, the equation gives 25 mL of stock and 500 mg of ingredient. The final volume is 100 mL, not automatically 25 plus 75 mL after mixing.
The same ingredient must be on both labels
The stock and target concentrations must describe the same specified ingredient on a comparable mg/mL basis. OpenStax derives C₁V₁ = C₂V₂ from conserving the amount of solute on dilution. Here that conserved quantity is ingredient mass in milligrams.
Final volume is the endpoint
The displayed difference between final volume and stock volume is a planning difference, not a guaranteed physical volume of diluent to pour. Some mixtures change volume on combining. A laboratory protocol may specify bringing the mixture to the final volume, with compatibility and measurement rules outside this calculator.
No clinical instruction
Do not use this result to set a medication dose, route, patient-specific amount, or mixing procedure. Verify identity, concentration basis and any applicable professional protocol independently. The arithmetic runs locally; your inputs are not transmitted.
Explore the related calculation
For a different starting point, try the concentration comparison or return to the main calculator. Browse the complete tool directory for this site.
Reference and corrections
The definitions and assumptions above follow these sources; the examples and calculator arithmetic are original to this page.
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