๐งซ Dilution Calculator (C1V1=C2V2)
Leave only the one value you want to solve for blank, and enter the other three.
Use the widely-used dilution formula "C1V1 = C2V2" (initial concentration ร initial volume = final concentration ร final volume) to solve for whichever one of the four values you leave blank, given the other three. Units follow whatever you enter, so use a consistent unit system throughout.
How to use
- Leave blank whichever one of the four values (C1, V1, C2, V2) you want to calculate.
- Enter the other three values.
- The blank value is calculated automatically.
How the calculation works
This tool uses the dilution formula CโVโ = CโVโ to solve for whichever of the four values you leave blank. Cโ is the starting concentration, Vโ the volume of stock solution used, Cโ the final concentration, and Vโ the final total volume. Diluting with water or another solvent does not change the amount of dissolved substance (solute), so "concentration ร volume" is the same before and after. Rearranged, each value is: Vโ = Cโ ร Vโ รท Cโ (how much stock to use) Cโ = Cโ ร Vโ รท Vโ (the diluted concentration) Vโ = Cโ ร Vโ รท Cโ (the total volume to make up to) Cโ = Cโ ร Vโ รท Vโ Any units work โ %, mol/L, mg/mL, mL, L โ as long as both concentrations use the same unit and both volumes use the same unit.
Worked example
Making 100 mL of a 1% solution from a 10% stock Vโ = 1 ร 100 รท 10 = 10 mL Take 10 mL of stock and add water to a total of 100 mL (that is, add 100 โ 10 = 90 mL of water). Making 1 L of 0.05% solution from 6% sodium hypochlorite (household chlorine bleach) Vโ = 0.05 ร 1000 รท 6 โ 8.3 mL Add water to about 8.3 mL of bleach to make 1 L in total.
Things to be aware of
- Vโ is the final total volume, not the amount of water to add. The water to add is Vโ โ Vโ.
- For liquids whose volumes change when mixed, such as alcohol and water, the actual amounts will differ slightly from the calculation.
- Mixing chlorine bleach with acidic cleaners releases toxic gas. When diluting chemicals, follow the product label and work in a ventilated area.
FAQ
What does C1V1=C2V2 mean?
It expresses conservation of the total amount of solute (moles or mass) during dilution: initial concentration ร initial volume (C1V1) equals final concentration ร final volume (C2V2).
What units should I use?
Use a consistent unit for concentration (C1, C2) and a consistent unit for volume (V1, V2) โ e.g. concentration in mol/L or %, volume in mL or L. Mixing units will give an incorrect result.
What if two or more values are left blank?
This tool can only solve when exactly one of the four values is left blank. No result is shown if two or more are blank.