What is PPM and How Do I Convert It



PPM stands for Parts Per Million, a unit of measure used to determine the number of parts of a material that is present in one million parts of the same material. This unit of measure is commonly used for measurements related to water quality and is used to express the concentrations of chemical elements, toxic compounds, and other materials.

In this article, we will discuss how to convert PPM to other units of measurement.

Definition of PPM

Parts per million (PPM) is a way of expressing very dilute concentrations of substances. Generally, it is used to measure the concentration of substances in a solution, solids or gasses. PPM is an expression of the atomic or molecular mass (varying for different elements) of a substance in the unit volume which indicates how much one mole of this substance is present in 1 million units of the same system.

In simple terms, it means that if you have 79 atoms of gold dispersed in every 1 million atoms, then the concentration of gold will be 79 ppm (79 parts per million). This value can also be expressed as 7.9 parts per 100 thousand or 790 parts per billion. It can also be expressed as milligrams per liter moles per cubic centimeter and more depending on context and type of measurement.

PPM measurements are used mainly because they allow us to measure very low concentrations without worrying about significant discrepancies due to inaccuracies in the measurement apparatus itself. Using devices with high precision, it is possible to measure concentrations down to even single atom ppm solution range.

Types of PPM

PPM stands for Parts Per Million and is used commonly in scientific and technical contexts. It is a measurement for density, referring to the ratio of particles present in a given volume. It can be used to measure contaminants, pollutants or other substances.

In chemistry and engineering, there are two main types of PPM measurement: volume (V) and mass (M). Volume PPM refers to the number of particles per given volume, such as milliliters (ml). Mass PPM refers to the amount of material per given mass such as kilograms (kg).

PPM measured either way can be converted easily with an appropriate formula. The usual formula is: 1 V-PPM = 1 M-PPM x X/Y where X is the molecular weight of the material being measured, Y is the molecular weight of water, and M represents mass (kg) or volumetric (ml) dependent on which type of PPM we are converting from.

It’s important to note that both M-PPM and V-PPM have different operating ranges depending on the material being measured; for instance, extremely small particles like hazardous dust may operate at V-PPM measurements under 1 million whereas relatively large organic molecules may operate between 10 million and 1 billion when measuring by means of M-PPM.


PPM, or parts per million, is a metric used to measure the concentration of a given molecule in a solution. Converting between other units and PPM can be done using simple calculations. In this section we will cover the calculations and conversions you’ll need to make when working with parts per million.

Conversion of PPM to Other Units

Parts per million (PPM) is a measure of the concentration of a substance in a given sample, which is expressed as a fraction of one million. It’s used in various fields to measure 1,000 milligrams/kilogram (1/1,000,000). PPM can be expressed as either mass/volume or weight/mass.

For environmental and health studies, the weight/mass method is advised. The calculation for PPM using mass involves dividing the total mass by the total volume of solids and liquids. When measuring airborne pollutants and ionizing radiation strength, concentration can be measured using pico-curies per liter (pCi/L).

When converting PPM to other units such as moles per cubic meter (mol/m3), there are several variables to consider including temperature, pressure and chemical composition. With current laboratory and online calculators it is easy to convert between various units such as parts per million to milligrams per liter (mg/L); for instance 1ppm = 1 mg ∙ L–1. This conversion factors in elements with different densities based on their chemical makeups—but it doesn’t necessarily factor in temperature or pressure effects that may exist depending on your equation.

Calculating PPM

Parts Per Million (PPM) is a measurement of the concentration of a solution. It refers to how many “parts”, or molecules, of one substance are present for every 1 million parts (by weight or volume) of solution. PPM can be used to measure the concentration of anything falling within these two categories – making it an incredibly versatile form of measurement!

PPM can become fairly complex depending on what needs to be measured, however understanding the basic formula can simplify your calculations:

  • PPM = Mass Concentrated/VolumeofSolution * 1,000,000
  • Where Mass Concentrated is equal to moles of solute/atomic weight in grams per liter.

For example, if you wanted to calculate the PPM of 6 g NaCl (sodium chloride) in 2 L of water:

  • PPM = 6 g NaCl/2L *1,000,000
  • = 3,000 PPM

This means that there are 3 parts per million (6 grams) sodium chloride present in this solution. Similarly you could use this equation to figure out how much something needs to weigh if you want a certain PPM level too – just isolate the mass in your equation and solve accordingly.


PPM stands for parts per million and it is a measure of concentration of a substance in a sample. This type of measure is often used in industries such as food, agriculture, and manufacturing. It is important to be able to convert PPM to more traditional measurement units such as grams and kilograms.

Let’s look at the common applications of PPM and the process of converting between measurement units:

Environmental Monitoring

Environmental monitoring is a process used to assess the presence of pollutants, soil contaminants, and other harmful materials within a particular environment. Groups such as government agencies, industry regulators, and private consultants use the results of environmental monitoring efforts to help reduce potential risks on humans, plants, and animals. Methods for collecting information can vary depending on the type of pollutant being monitored.

One common practice used in environmental monitoring is testing for parts-per-million (PPM). PPM testing determines how much of a pollutant is present in an environment or within a test sample collected from that environment. Generally speaking, PPM values that measure up to or near 1 million indicate incredibly minuscule concentrations are present. Once data has been collected through environmental sampling techniques, it must be converted in order to adequately interpret it.

Converting Parts per Million: For scientific experiments or research studies conducted on pollutants where data needs to be converted into PPM values (or vice versa), special instruments are generally needed for accurate results. Equipment such as liquid chromatographs are also often used when examing particulate matter found in water samples. Such instruments can measure specific chemical substances down to 0.01 parts per billion concentrations – which yields drastically more precise readings than standard PPM testing procedures allow for.

Industrial Processes

For industrial processes, measurement and control of concentrations, often using PPM, is critical for the safe operation of industrial systems and processes. From the production of chemicals and medicines to confectionery and food production, understanding the concentration of ingredients and controlling them during plant operations is critical for success.

PPM represents mass/volume over time for a given substance where typically one million represents one part per million or one milligram per kilogram or liter. For example, 1 part per million could mean 36 grams in an oil refinery tank or 1 ppm could mean 0.020 milligrams in a liter of river water.

When it comes to basic conversions from PPM to other units, the actual number doesn’t usually matter as much as knowing your starting numerical unit (or conversion factor). To convert ppm to percent, divide by 10 000; to convert ppm to mg/L, multiple by 1000; to convert percent (by volume) to mg/L multiply by 10 000; and so on. Each situation will require different conversion factors depending on the element being converted. For example, converting nitrogen dioxide from parts per million to milligrams per cubic metre would require different calculations than converting hydrogen sulfide from parts per million into milligrams per cubic metre.

Advantages and Disadvantages

Parts per million (PPM) is a unit of measurement used in many different types of industries. It helps to measure the quantity of contaminants in liquids or gases. Converting between parts per million and other units of measurement can be a challenge but it is an important task.

Before attempting to convert between units, it is important to understand the advantages and disadvantages of using PPM:

Advantages of PPM

PPM (parts per million) is a unit of measurement used to quantify the amount of one substance dissolved in another, typically a liquid or gas. This unit is especially useful in the field of environmental science, where it is used to measure pollutants and other chemicals. As PPM is a very important concept in both physical and biological sciences, it is necessary to understand the advantages this type of measurement offers.

The main advantage of PPM as a unit of measurement lies in its ability to measure trace elements accurately. Many materials are present in small concentrations that may not be detectable with larger units but can be accurately determined with PPM measurements. By measuring the concentration of chemicals or pollutants precisely, scientists are able to track subtle changes in water quality over time or compare levels across different sites more accurately.

Another advantage offered by PPM is that its measurements remain unchanged regardless of the volume being measured. As a result, comparing different samples remains consistent even if there are significant differences between sample sizes or containers being used. This benefit makes it easier for scientists to compare results without having to worry about potential discrepancies caused by varying volumes.

Finally, because measurements taken using PPM are based on actual data points extracted from analyses, they can be easily compared against established standards and regulatory limits set by government bodies such as the Environmental Protection Agency (EPA). This helps ensure compliance with regulatory standards while also providing valuable insight into environmental conditions such as water quality or soil contamination levels.

Disadvantages of PPM

Though parts per million (PPM) is commonly used as a measure of concentration in numerous industries, it does have its share of drawbacks. One primary disadvantage of using PPM is its use of the unit ‘per million’ which only works when you have a large number of samples. For example, if there are only two samples to compare a PPM measurement will not be reliable.

In addition, when comparing two different concentrations, an entire additional calculation needs to be conducted with PPM due to the fact that it operates on a per million scale; so direct comparison cannot be done one-to-one. Finally, PPM is not useful in situations where dynamic concentrations need to be measured – meaning those that can vary over time or space. Measurements like this require other units such as moles per liter (M/L).


After exploring PPM and the different ways of converting PPM values, it is clear that there are many benefits to working with this unit of measurement. For one, PPM allows you to easily compare concentrations of different chemical compounds within a solution and accurately evaluate chemical concentrations relative to one another. Additionally, the ease of conversion between different units and scales of measurement makes PPM a reliable and versatile unit of measurement that is applicable in any situation.


In summary, parts Per Million (PPM) is a unit of measurement to express the amount of a chemical or contaminant per unit volume of water. A liter or cubic meter of water contains approximately one million milligrams, so one PPM is equal to one milligram/liter (mg/L). Converting from PPM to mg/L can be accomplished by firstly determining the conversion factor between the two units, then using that factor to convert the given PPM.

It is important to note that when converting from PPM to mg/L, temperature and salinity must also be taken into consideration in order for the result to be accurate. There are also various online tools available for direct PPM conversions if you don’t wish to do manual calculations.

Further Reading

To learn more about parts-per-million (ppm) and how to convert it, check out the following resources:

  1. Parts Per Million Basics – Learn what ppm stands for, how it works and how to read ppm measurements.
  2. How to Convert Parts Per Million Values – Find out how to convert between ppm values, such as from mg/L to μg/m3 or g/mL.
  3. Understanding the Practice of Dilutions – Learn how dilution factors apply when converting between concentration values, including ppm.
  4. Conversions Table – Quickly find easy-to-use charts and tables that convert concentrations between common units like μg/ml and mg/L.
  5. Calculators – Find helpful calculators for converting between concentrations for use in your calculations or processes.