Analytical concentration conversion
PPM to Molarity Calculator
Convert ppm or ppb to molarity using molar mass. Free lab calculator for mg/L, µg/L, mol/L, mM, µM, and nM conversions.
Convert
Your converted concentration will appear here
ppm = M × MW × 1000ppm (mg/L) = M × MW (g/mol) × 1000·ppb (µg/L) = ppm × 1000Example: convert 58.44 ppm NaCl to molarity
- 1Treat 58.44 ppm in water as 58.44 mg/L.
- 2Convert to grams per liter: 0.05844 g/L.
- 3Divide by NaCl molar mass, 58.44 g/mol.
- 4Result: 0.001 mol/L, or 1 mM.
Common mistakes to avoid
- Assuming ppm always equals mg/L outside dilute aqueous solutions.
- Forgetting to convert ppb to µg/L before molarity conversion.
- Using the wrong molar mass for hydrates, salts, or specific chemical forms.
Frequently asked questions
Is ppm the same as mg/L?
For dilute aqueous solutions, ppm is commonly approximated as mg/L. For other matrices or high-precision work, verify the density and reporting convention.
How do I convert ppb to molarity?
Convert ppb to µg/L, then to g/L, then divide by molar mass in g/mol. LabTools handles the arithmetic once you enter the molar mass.
Why do I need molar mass?
Molarity counts moles per liter, while ppm reports mass per volume or mass fraction. Molar mass connects mass to moles.
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Open the working LabTools calculator with units, validation, and prep-sheet output.