Convert mass concentration (g/L, mg/L or µg/L) to molar concentration (mol/L, mmol/L, µmol/L) using the molar mass.
Result
How to use this tool
Enter the value and choose g/L, mg/L or µg/L.
Enter the substance’s molar mass in g/mol.
Read mol/L, mmol/L and µmol/L.
Confirm the unit choice before using the result in a calculation.
Formula & worked example
Glucose at 1000 mg/L (1 g/L) with a molar mass of 180.156 g/mol converts to 1 / 180.156 ≈ 0.005551 mol/L = 5.551 mmol/L.
Limitations — read this before you rely on it
Unit conversion only; it cannot identify an unknown substance, and the molar mass must match the actual compound and hydration state.
Frequently asked questions
Mass concentration weighs the solute per litre; molar concentration counts molecules (moles) per litre.
A gram of a heavy molecule contains fewer molecules than a gram of a light one, so the conversion depends on the substance.
Sum the standard atomic weights of the formula’s atoms, or look it up for the compound.
Convert to mg/L first by multiplying by 10, then use this tool.
Only through volume changes: molarity is defined at the stated temperature, but for dilute aqueous solutions the effect is small.