mM

millimole per liter

Molar concentrationexact by definition

The millimole per litre, symbol mM, is one thousandth of a molar and is exactly equal to one mole per cubic metre. The factor of 1 relative to mol/m³ is exact. It is the standard unit of clinical chemistry outside the United States: blood glucose is reported in mmol/L, as are sodium, potassium and calcium.

Watch out: US clinical laboratories report most analytes in mg/dL instead, and converting between the two needs the molar mass. Blood glucose at 5.5 mmol/L is 99 mg/dL, a factor of about 18 that comes from glucose's molar mass of 180 g/mol.

1 mM 0.001 M