Dilution
Solve C₁V₁ = C₂V₂ for the value you do not know.
Result
Stock volume (V₁) 0.5 mL
Stock to take 500 µL
Diluent to add 49.5 mL
Dilution 100× (1 in 100)
Formula
The amount of substance is conserved: C₁ × V₁ = C₂ × V₂. The diluent to add is V₂ − V₁. A warning appears when the requested final concentration exceeds the stock.
Questions
What does C1V1 = C2V2 mean?
The amount of solute does not change when you dilute, so concentration times volume before dilution equals concentration times volume after. Rearrange to find whichever of the four values you do not know.
How much stock do I need to make 50 mL of 10 mM from a 1 M stock?
V1 = C2 × V2 ÷ C1 = 0.010 × 50 ÷ 1 = 0.5 mL. Add 0.5 mL of stock to 49.5 mL of diluent.
Can I use different units for the two concentrations?
Yes, as long as each pair matches. The calculator converts everything to base units internally, so mixing millimolar and micromolar is fine.