Work out how much stock solution to take, or what concentration you will end up with, using C₁V₁ = C₂V₂. Enter any three of stock concentration, volume of stock, final concentration and final volume, and this calculator returns the fourth — then tells you exactly how much solvent to add and how to p...
Three values entered — solving for volume of stock to take.
solved: 50.0000 mL
COMMON DILUTIONS
TAKE THIS MUCH STOCK
50.00 mL
ADD SOLVENT
450.0 mL
DILUTION FACTOR
10.00 ×
SOLUTE MOVED
0.0500 mol
Stock C₁
1.0000 M
Stock volume V₁
50.0000 mL
Final C₂
0.1000 M
Final volume V₂
500.000 mL
Ratio stock:final
1 : 10.00
Stock as % of final
10.000 %
HOW TO PREPARE IT
Measure 50.00 mL of the 1.000 stock solution.
Put it into a vessel that will hold at least 500.00 mL.
Add solvent until the total reaches exactly 500.00 mL — about 450.0 mL, though the mark is what counts, not the amount added.
Mix thoroughly. The result is 0.1000, a 10.00× dilution.
THE TRANSFER
Why C₁V₁ = C₂V₂ works. Adding solvent does not create or destroy any solute, so the amount of solute is identical on both sides — 0.0500 mol here. Since amount is concentration times volume, C₁V₁ and C₂V₂ are two ways of writing that same unchanged quantity, which is why the equation holds whatever units you use, as long as you are consistent on both sides.
Repeating a dilution multiplies the effect. Six rounds of this 10.00× step would leave a concentration 1.0000e-6 of where you started — which is how laboratories reach very low concentrations accurately, rather than trying to measure a tiny volume in one go.
HOW BIG A DILUTION IS THAT?
Live simulation · updates as you type
Enter any three of the four boxes — stock concentration C₁, volume of stock to take V₁, final concentration C₂, and final volume V₂. Known values get a solid black border; the one you leave blank is outlined in gold and fills in automatically.
Pick units beside each field. Concentration in molar down to nanomolar, or in percent w/v and grams per litre — the units cancel on both sides, so any consistent pair works. Volumes in litres, millilitres, microlitres or decilitres.
Read the answer, then the three figures beside it: how much solvent to add, the dilution factor, and the amount of solute being moved. The solvent figure is the one you need at the bench.
Follow the four preparation steps. Note step three in particular — make the solution up to the final volume rather than adding that volume of solvent, because the mark is what defines the concentration.
Last updated: July 29, 2026 · Formula verified · Eagle-eyed accuracy for every calculation.