Molarity ↔ ppm Converter (dilute aqueous)

Environmental and analytical chemistry report trace concentrations in ppm (mg/L), while the bench works in molarity. For dilute water solutions — where 1 L weighs ~1 kg — this tool converts either way using the solute's molar mass.

Molarity ↔ ppm Converter (dilute aqueous)

$ppm = M(mol/L) \times M(g/mol) \times 1000$

Solve for

Molarity (M)

Unit

Solute molar mass (M_solute)

Unit

Result unit

How to interpret the result

Worked check: 0.100 M NaCl (58.44 g/mol) → 0.100 × 58.44 × 1000 = 5844 ppm. Seawater's ~35000 ppm salts is about 0.6 M — the same math in reverse.

Assumptions

Dilute aqueous solution with density ≈ 1.00 g/mL
ppm means mg of solute per liter of solution here