milligram per liter
DensityConcentrationexact by definition
The milligram per litre is exactly 10⁻³ kilograms per cubic metre. It is the universal reporting unit of water analysis: hardness, alkalinity, chloride, iron and every regulated contaminant in drinking water are given in mg/L.
Watch out: In dilute aqueous solution mg/L and ppm are treated as interchangeable, and for water near 1000 kg/m³ that is accurate to well under a percent. The equivalence fails for anything else. In a brine, in a solvent, in soil or in air, ppm by mass and mg/L differ by the density, and in air quality work "ppm" usually means by VOLUME, which is a different quantity again.
| 1 (Density) | 0.001 |
| 1 (Concentration) | 0.0001 |
The milligram per litre is treated here as 10⁻⁴ percent, equal to one part per million, which holds for any solution dilute enough that a litre still weighs a kilogram. It is the unit of nearly every water analysis: hardness, alkalinity, chloride, iron and total dissolved solids all arrive in mg/L.
One milligram per liter in every density unit
| 1,000 | microgram per liter (μg/L) | |
| 1,000 | milligram per cubic meter (mg/m³) | |
| 1 | milligram per liter (mg/L)this unit | |
| 0.00168555 | pound per cubic yard (lb/yd³) | |
| 0.001 | kilogram per cubic meter (kg/m³) | |
| 0.001 | gram per liter (g/L) | |
| 0.000062428 | pound per cubic foot (lb/ft³) | |
| 0.0000100224 | pound per imperial gallon (lb/imp gal) | |
| 0.0000083454 | pound per US gallon (lb/gal) | |
| 0.00000194032 | slug per cubic foot (slug/ft³) | |
| 0.000001 | gram per cubic centimeter (g/cm³) | |
| 0.000001 | gram per milliliter (g/mL) | |
| 0.000001 | kilogram per liter (kg/L) | |
| 0.000001 | tonne per cubic meter (t/m³) | |
| 8.42777e-07 | US short ton per cubic yard (ton/yd³) | |
| 3.61273e-08 | pound per cubic inch (lb/in³) |
One milligram per liter in every concentration unit
| 1,000,000 | part per trillion (ppt) | |
| 1,000,000 | nanogram per liter (ng/L) | |
| 1,000 | parts per billion (ppb) | |
| 1,000 | microgram per liter (μg/L) | |
| 1 | parts per million (ppm) | |
| 1 | part per million by volume (ppmv) | |
| 1 | milligram per kilogram (mg/kg) | |
| 1 | milligram per liter (mg/L)this unit | |
| 0.058418 | grain per US gallon (as CaCO₃) (gpg) | |
| 0.001 | part per thousand (ppth) | |
| 0.001 | gram per liter (g/L) | |
| 0.0001 | percent (%) | |
| 0.0001 | percent by weight (% w/w) | |
| 0.0001 | percent by volume (% v/v) | |
| 0.0001 | percent weight per volume (% w/v) | |
| 0.000001 | fraction (0–1) (fraction) |