About this tool
The Molarity & Dilution Calculator is a free, in-browser chemistry tool that finds the molar concentration of a solution, rearranges the dilution equation C1V1 = C2V2 for whichever quantity you leave blank, and lays out the concentrations of a serial dilution. In molarity mode you can type a chemical formula (for example NaCl or C6H12O6) and the molar mass is computed automatically from standard atomic weights, or you can enter the molar mass by hand.
Everything runs locally in your browser using plain JavaScript arithmetic — nothing you type is uploaded, logged, or sent to a server, so lab values and reagent amounts stay private on your device. The dilution mode expects exactly one empty field and solves for it; the serial mode repeatedly divides the stock concentration by a fold factor to list each tube.
Molarity is reported in mol/L (molar, M) with volume entered in millilitres and converted to litres internally. Concentration and volume units in the dilution equation are yours to choose, as long as both concentrations share one unit and both volumes share another.