Stock Solution Calculator
Mass to weigh for a stock solution, or solvent volume for a weighed amount, with purity correction and aliquot planning.
Mass to weigh
Working
About this tool
Plan a stock solution two ways: find the mass to weigh for a target concentration and volume, or find the volume of solvent that brings a weighed amount to a target concentration. A purity or net-content correction accounts for counter-ions and water in lyophilised material, and an optional aliquot size tells you how many aliquots the stock will give.
How to use it
- Choose Mass to weigh or Volume of solvent.
- Enter the target concentration in molar or mass-per-volume units. Molar units need the molecular weight.
- Enter the purity or net content from the certificate of analysis (100% if unknown).
Formula f(x)
mweigh = (c × V × M) / p for molar targets, or mweigh = (cmass × V) / p for mass-per-volume targets.
V = (m × p) / (c × M) when solving for volume, where p is purity or net content as a fraction.
Worked example check your setup
10 mL of a 10 mM stock of GHK (M = 340.38 g/mol) from material with 80% net content: m = (0.010 mol/L × 0.010 L × 340.38 g/mol) ÷ 0.80 = 42.55 mg. In 500 µL aliquots this gives 20 aliquots.