Solution concentration calculator
Work out the concentration of a laboratory solution from the mass of peptide and the volume of solvent, the volume needed to reach a target concentration, or a dilution from a stock solution.
Concentration from mass and volume
Volume for a target concentration
Dilution (C1V1 = C2V2)
Leave one box empty to solve for it. Give both concentrations in the same measure (for example mg/mL), and both volumes in the same measure (for example mL).
The formulas
Concentration (mg/mL) is mass divided by volume. Because 1 mg/mL equals 1 g/L, molarity is that number divided by the molecular weight: mol/L = (mg/mL) ÷ (g/mol). Multiply by 1,000 for millimolar (mM) or by 1,000,000 for micromolar (µM). Use the average mass from the molecular weight calculator or the certificate.
For dilutions, the amount of solute is the same before and after, so C1 × V1 = C2 × V2. Leave one of the four values empty and the calculator solves for it. Give both concentrations in the same measure, and both volumes in the same measure.
Worked examples
10 mg of BPC-157 in 2 mL of solvent is 5 mg/mL. With a molecular weight of 1419.53 g/mol, that is 3.522 mM, or 3522 µM.
To make 10 mL of a 1 mg/mL working solution from a 5 mg/mL stock, take 2 mL of stock and bring it to 10 mL.
Lyophilized material can hold residual water and counter-ions, so the peptide content of a vial can be lower than its labelled mass. Where a certificate reports net content, use that mass for precise molar work. How to read a certificate.
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