Enter any 2 values (ppm, molarity, and molar mass) into the calculator to determine the missing variable. For dilute aqueous solutions, ppm is commonly treated as mg/L.

Molarity To PPM (mg/L) Calculator

Enter any 2 values to calculate the missing variable (ppm is treated as mg/L)

G/Mol To Ppm Formula

The following formula is used to calculate ppm (commonly treated as mg/L for dilute aqueous solutions) from molarity and molar mass.

\text{ppm (mg/L)} = C \cdot MW \cdot 1000

Variables:

  • ppm is parts per million (often approximated as mg/L in dilute aqueous solutions)
  • C is the molar concentration (mol/L)
  • MW is the molar mass (g/mol)

To calculate ppm (mg/L), multiply the molarity (mol/L) by the molar mass (g/mol) and then multiply by 1000.

Molarity (mol/L) to PPM (mg/L) Conversion Table (Assuming NaCl, molar mass = 58.44 g/mol)
Molarity (mol/L) Molar Mass (g/mol) PPM (≈ mg/L)
1.711e-658.440.1
8.556e-658.440.5
1.711e-558.441
3.422e-558.442
8.556e-558.445
1.711e-458.4410
3.422e-458.4420
4.278e-458.4425
5.133e-458.4430
6.845e-458.4440
8.556e-458.4450
0.001026758.4460
0.001283458.4475
0.001711158.44100
0.002566758.44150
0.003422358.44200
0.004277958.44250
0.008555758.44500
0.012833658.44750
0.017111458.441000
Formula used: ppm (mg/L) = Molarity (mol/L) × Molar Mass (g/mol) × 1000. “ppm ≈ mg/L” is a common approximation for dilute aqueous solutions.

What is G/Mol To Ppm?

“g/mol” is a unit of molar mass (molecular weight), not a concentration. In many chemistry problems, ppm is used as a concentration unit (often treated as mg/L for dilute aqueous solutions). Using the molar mass (g/mol), you can convert between molarity (mol/L) and ppm (≈ mg/L) for solutions. Note: ppm conversions for gases (ppmv) or for non-aqueous mixtures require additional information (such as temperature, pressure, or density).

How to Calculate G/Mol To Ppm?

The following steps outline how to calculate ppm (≈ mg/L) from molarity using molar mass.


  1. First, determine the molarity (C) in mol/L.
  2. Next, determine the molar mass (MW) in g/mol.
  3. Next, calculate ppm (mg/L) using the formula: ppm (mg/L) = C × MW × 1000.
  4. If you need “true” ppm by mass (mg/kg), use the solution density to convert between mg/L and mg/kg.
  5. After inserting the values and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Molarity (C) = 0.002 mol/L

Molar mass (MW) = 50 g/mol