Enter the ppmv value and measurement context into the calculator to determine the equivalent ppm value. For gas-phase measurements reported on a volume basis, ppmv and ppm are usually numerically the same.

ppmv to ppm Converter

Enter a value in ppmv to convert it to ppm.

ppmv to ppm Formula

The following formula is used to convert ppmv to ppm for gas measurements reported on a volume basis.

PPM = PPMV

Variables:

  • PPM is the concentration in parts per million
  • PPMV is the concentration in parts per million by volume

On a volume basis, ppmv is typically defined as the volume fraction of a gas component multiplied by 106. When ppm is also being used on a volume basis, the numerical value does not change, so converting from ppmv to ppm is a one-to-one relationship.

What is ppmv to ppm?

Parts per million by volume (ppmv) expresses the amount of a gas relative to the total gas mixture using a volume ratio. In air quality, indoor air, industrial hygiene, and many stack gas applications, ppm for gases is also understood to be volume-based. Because of that, a reading such as 50 ppmv and 50 ppm usually represent the same concentration.

For example, 10 ppmv of carbon monoxide corresponds to 10 ppm carbon monoxide, and 420 ppmv of carbon dioxide corresponds to 420 ppm carbon dioxide, provided the concentration is being interpreted on the same volume basis and under the same reference conditions.

  • Ambient and indoor air monitoring: ppm and ppmv are generally interchangeable
  • Stack gas reporting: ppm is normally volume-based unless stated otherwise
  • If ppm is defined on a mass basis instead of a volume basis, a separate density or molar-mass conversion is required

ppmv to ppm Conversion Table

The table below shows example conversions for a 10 ppmv concentration of several gases. Because ppmv and ppm are numerically equal on a volume basis, the ppm value is also 10 in each case.

Gas / application Typical measurement context 10 ppmv in ppm
Ozone (O₃) Ambient air quality 10 ppm
Carbon monoxide (CO) Workplace exposure limit 10 ppm
Nitrogen dioxide (NO₂) Urban air monitoring 10 ppm
Sulfur dioxide (SO₂) Stack / flue gas sampling 10 ppm
Volatile organic compound (VOC) Indoor air investigation 10 ppm
Methane (CH₄) Natural gas leak detection 10 ppm
Generic trace gas Any dilute gas mixture (volume fraction) 10 ppm

Laboratories, regulators, and instrument manuals may switch between the notations ppmv and ppm when discussing gas concentrations. Recognizing that these are numerically equivalent on a volume basis makes it easier to interpret readings and compare values across different sources.

How to Convert ppmv to ppm?

The following steps outline how to convert ppmv to ppm.


  1. First, determine the gas concentration in ppmv.
  2. Next, confirm that the concentration is being reported on a volume basis under the same reference conditions.
  3. Finally, apply the formula PPM = PPMV.
  4. After inserting the value 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.

ppmv = 50

ppm = 50