Enter the concentration in nanograms per milligram (ng/mg) into the calculator to convert it to parts per million (ppm). For standard mass-by-mass measurements, ng/mg and ppm are numerically identical, so the value stays the same after conversion.

ng/mg to ppm Converter

Enter a value in ng/mg to convert it directly to ppm.

On a mass-per-mass basis, 1 ng/mg = 1 ppm.

Quick Overview

For mass-per-mass concentrations, nanograms per milligram and parts per million describe the same ratio: 10-6 grams of analyte per gram of sample.

  • 0.1 ng/mg = 0.1 ppm
  • 1 ng/mg = 1 ppm
  • 5 ng/mg = 5 ppm
  • 10 ng/mg = 10 ppm

The calculator returns the same numeric value in ppm, assuming a standard weight-by-weight concentration basis.

ng/mg to ppm Formula

The following relationship is used to convert nanograms per milligram (ng/mg) to parts per million (ppm) for mass-by-mass concentrations.

ppm = ng/mg

This works because 1 ng = 10-9 g and 1 mg = 10-3 g, so:

  • 1 ng/mg = 10-9 g / 10-3 g = 10-6 g/g
  • 1 ppm = 10-6 g/g
  • Therefore, the numerical value does not change when converting from ng/mg to ppm.

In other words, if a sample contains 3.5 ng of analyte per mg of material, that concentration is exactly 3.5 ppm on a mass-per-mass basis.

What is ng/mg to ppm?

ng/mg to ppm is a unit conversion used in laboratory, environmental, and materials analysis to express the same concentration in a different format. Nanograms per milligram is a mass-per-mass concentration, while parts per million is a dimensionless way to state that same fraction. Since both units represent a ratio of one part in a million, they are numerically equal for standard weight-by-weight measurements.

How to Convert ng/mg to ppm?

The following steps outline how to convert ng/mg to ppm.


  1. First, determine the concentration in ng/mg.
  2. Next, recognize that 1 ng/mg is equal to 10-6 g/g.
  3. Then use the definition 1 ppm = 10-6 g/g.
  4. Finally, keep the same numeric value when converting from ng/mg to ppm.
  5. Check your answer with the calculator above.

Example Problem:

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

Value in ng/mg = 12

Equivalent concentration in ppm = 12

Since ng/mg and ppm are identical on a mass/mass basis, the converted value remains 12 ppm.

ng/mg to ppm Conversion Table

The table below lists several common ng/mg concentrations and their equivalent values in ppm, along with the corresponding mass fraction in grams per gram.

ng/mg Equivalent ppm Mass fraction (g/g)
0.1 ng/mg 0.1 ppm 1.0 × 10-7 g/g
0.5 ng/mg 0.5 ppm 5.0 × 10-7 g/g
1 ng/mg 1 ppm 1.0 × 10-6 g/g
5 ng/mg 5 ppm 5.0 × 10-6 g/g
10 ng/mg 10 ppm 1.0 × 10-5 g/g
50 ng/mg 50 ppm 5.0 × 10-5 g/g

Laboratory reports may present results in either ng/mg or ppm depending on the instrument, method, or reporting standard. Knowing that these units are numerically equal for mass-per-mass data makes it easier to compare results across different reports and reference values.