Enter the concentration in mg/L into the converter to determine the approximate value in ppt for dilute aqueous solutions such as freshwater, seawater, or wastewater.

mg/L to ppt Converter

Enter a concentration in mg/L to convert it to parts per thousand (ppt).

For water-like liquids, 1 ppt is approximated as 1,000 mg/L, so the converter uses: ppt = mg/L ÷ 1,000.

mg/L to ppt Formula

The following formula is used to calculate the approximate value in parts per thousand from a concentration in milligrams per liter for water-like solutions.

ppt = mg/L / 1000

Variables:

  • ppt is the concentration in parts per thousand
  • mg/L is the concentration in milligrams per liter
  • 1000 is the conversion factor used for dilute aqueous solutions with density close to 1 g/mL

To calculate ppt from mg/L, divide the mg/L value by 1,000. This approximation is commonly used for freshwater, seawater, and other water-based samples when the density is close to that of water.

What is mg/L to ppt Conversion?

Milligrams per liter (mg/L) measures the mass of solute in each liter of solution, while parts per thousand (ppt) expresses concentration as a fraction of one thousand parts. For dilute aqueous systems, 1 liter of water has a mass of about 1 kilogram, so 1,000 mg/L is approximately equal to 1 ppt. This makes it easy to convert between the two units by dividing the mg/L value by 1,000.

mg/L to ppt Conversion Table

The table below shows several example conversions using the approximation ppt = mg/L ÷ 1,000.

Concentration (mg/L) Approximate fraction Value in ppt
50 mg/L 0.00005 0.05 ppt
100 mg/L 0.00010 0.10 ppt
500 mg/L 0.00050 0.50 ppt
1,000 mg/L 0.00100 1.00 ppt
2,000 mg/L 0.00200 2.00 ppt
10,000 mg/L 0.01000 10.00 ppt

How to Convert mg/L to ppt?

The following steps outline how to convert mg/L to ppt.

  1. First, determine the concentration in mg/L.
  2. Next, confirm the sample is a dilute water-based solution where 1 ppt ≈ 1,000 mg/L is a reasonable approximation.
  3. Then divide the mg/L value by 1,000 using the formula ppt = mg/L ÷ 1,000.
  4. After calculating the result, check your answer with the converter above.

Example Problem:

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

Concentration (mg/L) = 2,000

Solution Type = Freshwater

Result (ppt) = 2.0

For another example, 50 mg/L corresponds to 0.05 ppt, while 10,000 mg/L corresponds to 10 ppt.