Haemoglobin Unit Converter

In short Haemoglobin is reported in g/dL in some countries and mmol/L in others, and the two are related by a fixed factor: 1 g/dL = 0.620559 mmol/L, so to go the other way you divide by 1.61145. 12 g/dL is 7.4 mmol/L; 13.5 g/dL is 8.4 mmol/L; 15 g/dL is 9.3 mmol/L. The factor is not arbitrary — it comes from the molar mass, because the conversion uses the haemoglobin monomer, 16114.5 g/mol, and that is why every analyte has its own factor rather than one shared conversion. Haemoglobin has three reporting conventions, and two of them are only a factor of ten apart: g/dL and g/L. A result of 135 is g/L and the same result is 13.5 in g/dL, which is usually obvious — but mmol/L, used in the Netherlands and parts of Scandinavia, gives 8.4 for the same sample and is genuinely easy to misread. This converts units. It does not interpret results, does not compare your value against a reference interval, and is not a substitute for the clinician who ordered the test — reference intervals differ between laboratories, methods and populations.