Concentration Dilution Calculator Guide
Overview
The Concentration Dilution Calculator uses the fundamental chemistry equation C₁V₁ = C₂V₂ to help you prepare diluted solutions accurately. Whether you're working in a research lab, preparing buffer solutions, or conducting chemical analysis, this tool calculates any missing value when you provide the other three. The equation states that the amount of solute remains constant during dilution—only the volume and concentration change.
Inputs & Usage
You need to provide any three of the four values: initial concentration (C₁), initial volume (V₁), final concentration (C₂), and final volume (V₂). The initial concentration represents your stock solution, while the final concentration is what you want to achieve. Volumes must use consistent units (both in mL, both in L, etc.), and concentrations must also be consistent (both in M, both in mg/mL, etc.). Leave the value you want to calculate blank, and the calculator will solve for it automatically.
How It Works
The dilution equation is based on the principle that the number of moles (or mass) of solute stays the same before and after dilution. When you add solvent, the volume increases and the concentration decreases proportionally. The calculator rearranges this equation to solve for whichever variable is missing: , , and so on.
Interpreting the Results
The calculator shows all four values plus two additional helpful metrics. The dilution factor tells you how many times more dilute the final solution is compared to the stock—for example, a 5× dilution means the final solution is five times less concentrated. The volume to add shows how much additional solvent you need to reach the final volume from your initial volume of stock solution.
Example
Suppose you have a 5 M stock solution and want to prepare 100 mL of a 1 M working solution. Enter C₁ = 5, C₂ = 1, and V₂ = 100. The calculator determines you need V₁ = 20 mL of stock. To prepare it: measure 20 mL of the 5 M stock into a container, then add water (or appropriate solvent) until the total volume reaches 100 mL. This represents a 5× dilution.
Limitations
This calculator assumes ideal mixing with no volume changes upon dilution, which is valid for most aqueous solutions. It does not account for non-ideal behavior, density changes, or situations where mixing two liquids produces a final volume different from the sum of the individual volumes. Use it for standard laboratory dilutions where such effects are negligible.