How to Use the Dilution Calculator
Use the calculator to solve one quantity in C₁V₁ = C₂V₂ from the other three. The selected field is hidden, so enter the remaining values.
- Choose Stock concentration (C₁), Stock volume (V₁), Target concentration (C₂), or Final volume (V₂) in Solve for.
- Enter the other three values. Use the same concentration family for C₁ and C₂: both molar or both mass-based. Volume fields may independently use L, mL, or µL.
- Click Calculate. Use Copy result or Download result (.txt) to save the plain-text output.
- Use Reset to clear the values, restore the default units and selection, hide the result, and clear errors.
Dilution Formula and Supported Inputs
The tool uses:
C₁V₁ = C₂V₂, where C₁ is Stock concentration, V₁ is Stock volume, C₂ is Target concentration, and V₂ is Final volume.- Concentration units: M, mM, µM, mg/mL, g/L, and % w/v.
- Volume units: L, mL, and µL.
Do not mix molar and mass-based concentration families. The calculator has no molar-mass information for converting between them.
What the Result Shows
After calculation, the result shows the selected quantity and steps containing the formula, given values, normalized calculation, and result. It does not list separate unit-conversion steps.
When both volumes are available and V₂ is at least V₁, Diluent to add is shown as V₂ − V₁. If V₁ is greater than V₂, that statistic is not displayed.
Validation, Assumptions, and Limitations
- Enter plain decimal, finite, positive numbers no larger than
1e12. Blank, non-numeric, zero, negative, and oversized values are rejected. - The calculation assumes constant solute amount, additive volumes, and uniform concentration after mixing.
- It does not convert molar and mass-based concentrations, look up molar mass, or model non-ideal mixing, volume contraction or expansion, temperature effects, density, or solute-solvent interactions.
- The result is not certified laboratory, pharmaceutical, or professional advice.
Entered calculator values and the calculation are processed locally in your browser.
Frequently Asked Questions
What is the dilution formula?
The dilution formula is C1V1 = C2V2, where C1 is the stock concentration, V1 is the stock volume, C2 is the target concentration, and V2 is the final volume.
Can this calculator solve for stock concentration or stock volume, not just the final result?
Yes. Choose the quantity in Solve for, then enter the other three known values. The calculator solves only the selected quantity; it does not choose an unknown or fill unspecified inputs.
What units does this calculator support?
Concentration supports M, mM, µM, mg/mL, g/L, and % w/v. Volume supports L, mL, and µL. C1 and C2 must use the same concentration family.
How much diluent do I need to add?
Diluent to add equals V2 minus V1. It is shown when both volumes are available and V2 is at least V1; otherwise it is omitted.
Does this tool account for volume changes on mixing or temperature effects?
No. It assumes additive volumes and uniform concentration after mixing. It does not model non-ideal mixing, volume contraction or expansion, temperature effects, density, or solute-solvent interactions.