basic

ppm to Molarity Conversion Calculator

Convert mg/L (≈ ppm in dilute aqueous solutions) into mol/L.

Convert a parts-per-million concentration of a solute (assumed numerically equal to mg/L in dilute aqueous solutions) to molarity using the solute molar mass: M = ppm × 10⁻³ / MW.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

ppm
g/mol

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

M (mol/L) = ppm · 10⁻³ / MW

In depth

Convert a parts-per-million concentration of a solute (assumed numerically equal to mg/L in dilute aqueous solutions) to molarity using the solute molar mass: M = ppm × 10⁻³ / MW.