ppm – parts per million

What is ppm?

ppm is an abbreviation of parts per million. ppm is a value that represents the part of a whole number in units of 1/1000000.

ppm is dimensionless quantity, a ratio of 2 quantities of the same unit.

For example: mg/kg.

One ppm is equal to 1/1000000 of the whole:

1ppm = 1/1000000 = 0.000001 = 1×10^-6

One ppm is equal to 0.0001%:

1ppm = 0.0001%

ppmw – abbreviation of parts per million weight, a subunit of ppm that is used for part of weights like milligrams per kilogram (mg/kg).

ppmv – abbreviation of parts per million volume, a subunit of ppm that is used for part of volumes like milliliters per cubic meter (ml/m3).

Parts-per notations

Other part-per notations are written here:

Chemical concentration

ppm is used to measure chemical concentration, usually in a solution of water.

Solute concentration of 1 ppm is solute concentration of 1/1000000 of the solution.

The concentration C in ppm is calculated from the solute mass m_solute in milligrams and the solution mass m_solution in milligrams.

C_(ppm) = 1000000 × m_solute / (m_solution + m_solute)

Usually the solute mass m_solute is much smaller than the solution mass m_solution.

m_solute ≪ m_solution

Then the concentration C in ppm is equal to 1000000 times the solute mass msolute in milligrams (mg) divided by the solution mass msolution in milligrams (mg):

C_(ppm) = 1000000 × m_{solute (mg)} / m_{solution (mg)}

The concentration C in ppm is also equal to the solute mass m_solute in milligrams (mg) divided by the solution mass m_solution in kilograms (kg):

C_(ppm) = m_{solute (mg)} / m_{solution (kg)}

When the solution is water, the volume of mass of one kilogram is approximately one liter.

The concentration C in ppm is also equal to the solute mass m_solute in milligrams (mg) divided by the water solution volume V_solution in liters (l):

C_(ppm) = m_{solute (mg)} / V_{solution (l)}

Concentration of CO₂

The concentration of carbon dioxide (CO₂) in the atmosphere is about 388ppm.

Frequency stability

The frequency stability of an electronic oscillator component can be measured in ppm.

The maximal frequency variation Δf, divided by the frequency f is equal to the frequency stability

Δf_(Hz) / f_(Hz) = FS_(ppm) / 1000000

For example

Oscillator with frequency of 64MHz and accuracy of ±400ppm, has frequency accuracy of

Δf_(Hz) = ±400ppm × 64MHz / 1000000 = ±25.6kHz

So the oscillator produces clock signal within the range of 64MHz±25.6kHz.

The supplied frequency variation is caused from temperature change, aging, supply voltage and load changes.

Decimal, percent, permille, ppm, ppb, ppt conversion calculator

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PPM conversions

How to convert ppm to decimal fraction

The part P in decimal is equal to the part P in ppm divided by 1000000:

P_(decimal) = P_(ppm) / 1000000

For example

Find the decimal fraction of 500ppm:

P_(decimal) = 300ppm / 1000000 = 0.0005

How to convert decimal fraction to ppm

The part P in ppm is equal to the part P in decimal times 1000000:

P_(ppm) = P_(decimal) × 1000000

For example

Find how many ppm are in 0.0073:

P_(ppm) = 0.0073 × 1000000 = 7300ppm

How to convert ppm to percent

The part P in percent (%) is equal to the part P in ppm divided by 10000:

P_(%) = P_(ppm) / 10000

For example

Find how many percent are in 6ppm:

P_(%) = 9ppm / 10000 = 0.0009%

How to convert percent to ppm

The part P in ppm is equal to the part P in percent (%) times 10000:

P_(ppm) = P_(%) × 10000

For example

Find how many ppm are in 6%:

P_(ppm) = 9% × 10000 = 90000ppm

How to convert ppb to ppm

The part P in ppm is equal to the part P in ppb divided by 1000:

P_(ppm) = P_(ppb) / 1000

For example

Find how many ppm are in 9ppb:

P_(ppm) = 9ppb / 1000 = 0.009ppm

How to convert ppm to ppb

The part P in ppb is equal to the part P in ppm times 1000:

P_(ppb) = P_(ppm) × 1000

For example

Find how many ppb are in 8ppm:

P_(ppb) = 8ppm × 1000 = 8000ppb

How to convert milligrams/liter to ppm

The concentration C in parts-per million (ppm) is equal to the concentration C in milligrams per kilogram (mg/kg) and equal to 1000 times the concentration C in milligrams per liter (mg/L), divided by the solution density ρ in kilograms per cubic meter (kg/m³):

C_(ppm) = C_(mg/kg) = 1000 × C_(mg/L) / ρ_(kg/m³)

In water solution, the concentration C in parts-per million (ppm) is equal to 1000 times the concentration C in milligrams per liter (mg/L) divided by the water solution density at temperature of 20ºC, 998.2071 in kilograms per cubic meter (kg/m³) and approximately equal to the concentration C in milligrams per liter (mg/L):

C_(ppm) = 1000 × C_(mg/L) / 998.2071_(kg/m³) ≈ 1_(L/kg) × C_(mg/L)

How to convert grams/liter to ppm

The concentration C in parts-per million (ppm) is equal to 1000 times the concentration C in grams per kilogram (g/kg) and equal to 1000000 times the concentration C in grams per liter (g/L), divided by the solution density ρ in kilograms per cubic meter (kg/m³):

C_(ppm) = 1000 × C_(g/kg) = 10⁶ × C_(g/L) / ρ_(kg/m³)

In water solution, the concentration C in parts-per million (ppm) is equal to 1000 times the concentration C in grams per kilogram (g/kg) and equal to 1000000 times the concentration C in grams per liter (g/L), divided by the water solution density at temperature of 20ºC 998.2071 in kilograms per cubic meter (kg/m³) and approximately equal to 1000 times the concentration C in milligrams per liter (mg/L):

C_(ppm) = 1000 × C_(g/kg) = 10⁶ × C_(g/L) / 998.2071_(kg/m³) ≈ 1000 × C_(g/L)

How to convert moles/liter to ppm

The concentration C in parts-per million (ppm) is equal to the concentration C in milligrams per kilogram (mg/kg) and equal to 1000000 times the molar concentration (molarity) c in moles per liter (mol/L), times the solute molar mass in grams per mole (g/mol), divided by the solution density ρ in kilograms per cubic meter (kg/m3):

C_(ppm) = C_(mg/kg) = 10⁶ × c_(mol/L) × M_(g/mol) / ρ_(kg/m³)

In water solution, the concentration C in parts-per million (ppm) is equal to the concentration C in milligrams per kilogram (mg/kg) and equal to 1000000 times the molar concentration (molarity) c in moles per liter (mol/L), times the solute molar mass in grams per mole (g/mol), divided by the water solution density at temperature of 20ºC 998.2071 in kilograms per cubic meter (kg/m³):

C_(ppm) = C_(mg/kg) = 106 × c_(mol/L) × M_(g/mol) / 998.2071_(kg/m³) ≈ 1000 × c_(mol/L) × M_(g/mol)

How to convert ppm to Hz

The frequency variation in hertz (Hz) is equal to the frequency stability FS in ppm times the frequency in hertz (Hz) divided by 1000000:

Δf_(Hz) = ± FS_(ppm) × f_(Hz) / 1000000

For example

Oscillator with frequency of 64MHz and accuracy of ±400ppm, has frequency accu0racy of

Δf_(Hz) = ±400ppm × 64MHz / 1000000 = ±25.6kHz

So the oscillator produces clock signal within the range of 64MHz±25.6kHz.

ppm to ratio, percent, ppb, ppt conversion table