1 g/m³ equals exactly
1.000 mg/m³
The gram per cubic meter (g/m³) and the milligram per cubic meter (mg/m³) are both units used to express very small mass concentrations in a large volume, typical of air quality measurements, fine particulates, and atmospheric contaminants. Since 1 g = 1,000 mg, the conversion factor is simply 1,000.
To convert a measurement from g/m³ to mg/m³, simply multiply the value by 1,000:
To convert from mg/m³ to g/m³, perform the inverse operation, dividing by 1,000:
These units are fundamental in air quality monitoring, where concentrations of fine particulates (PM10, PM2.5) and other atmospheric pollutants are typically expressed in micrograms or milligrams per cubic meter, since the actual concentrations involved are extremely small relative to the volume of air considered. In industrial filtration systems too, these units are the standard for specifying particle removal efficiency.