💧 Dilution Calculator
Solve C1·V1 = C2·V2 for any one unknown and see how much solvent to add. Enter three of the four values, choose your concentration and volume units, and read off the answer.
💧 Dilution result
Uses C1·V1 = C2·V2. Add the shown solvent to the stock aliquot to reach the final volume. For educational use — verify against authoritative sources and follow proper lab safety (always add acid to water, not the reverse).
Conserve the solute, add the solvent
Diluting doesn't change how much solute you have — only how much solvent surrounds it. That is why C·V stays constant, and why the calculator can hand you both the stock volume to draw and the solvent to add to hit your target concentration and volume.
Use the Molarity Calculator to make the stock in the first place, and the pH Calculator to see how diluting a strong acid or base shifts its pH.
❓ Frequently Asked Questions
What is the C1V1 = C2V2 equation?
It is the dilution equation: the moles of solute are conserved when you add solvent, so concentration × volume before equals concentration × volume after. C1 and V1 are the stock (concentrated) solution's concentration and volume; C2 and V2 are the final (diluted) solution's concentration and volume. Given any three, the fourth follows by rearranging — for example V1 = (C2 × V2) ÷ C1.
How much solvent do I actually add?
Take the stock aliquot volume you need (V1) and the final volume (V2); the solvent (e.g. water) to add is V2 − V1. The calculator shows this directly. To make 1 L of 1 M from a 10 M stock, you need V1 = (1 × 1) ÷ 10 = 0.1 L of stock and add 0.9 L of solvent to reach 1 L.
Can I mix units like mM and mL?
Yes. Choose a concentration unit (M, mM, µM, nM) and a volume unit (L, mL, µL); the tool normalises everything to molar and litres before solving, then converts the answer back. Just keep C1 and C2 in the same concentration unit and V1 and V2 in the same volume unit, which the selectors enforce.
Does this work for serial dilutions?
Each step of a serial dilution is one C1V1 = C2V2 calculation. Solve for the stock volume you transfer, then treat the diluted result as the new stock for the next step. For very large dilution factors, serial steps are more accurate than a single one because they avoid pipetting tiny volumes.
Any safety notes?
When diluting concentrated acids, always add acid to water (never water to acid) to disperse the heat safely, and wear appropriate protection. This tool is for educational use — verify against authoritative sources and follow proper lab safety.