Haemoglobin g/dL → mmol/L

Convert haemoglobin from g/dL to mmol/L

Sources last checked: 2026-11-03

Haemoglobin g/dL → mmol/L

Convert haemoglobin from g/dL to mmol/L

Haemoglobin (g/dL)

Fill in every field to see the result.

Converts units only; reference ranges depend on the laboratory, the assay and the patient.

Source: AMA Manual of Style, 11th ed. (Oxford Academic) — Units of measure converter, Table 2: Selected laboratory tests and conversion factors.Open

What is the Haemoglobin g/dL → mmol/L?

Haemoglobin is reported in mmol/L mainly in the Netherlands, while Germany, Austria, Turkey and the USA use g/dL and the UK and Scandinavia g/L. This converter multiplies by 0.6206, the AMA Manual of Style factor. The mmol/L convention counts the haem-carrying monomer (one globin chain with one haem), not the whole tetramer.

When to use it

Reading Dutch guidelines, letters or studies that quote Hb in mmol/L
Communicating a g/dL result to a colleague trained in the mmol/L system
Comparing serial values from labs in different countries

When not to use it

HbA1c — it is reported in mmol/mol (IFCC) or % (NGSP) and uses a separate converter
Converting to g/L — that is simply × 10 and has its own page

How it is calculated

Haemoglobin (mmol/L) = Hb (g/dL) × 0.6206

Clinical pearls and limitations

Converts units only; reference ranges depend on the laboratory, the assay and the patient.
1 g/dL = 0.6206 mmol/L; a full-tetramer convention would give values four times lower, which is why the monomer basis must be stated.
Report mmol/L to one decimal place, as Dutch labs do.
Related red-cell indices in the Dutch system (MCH in fmol, MCHC in mmol/L) also use the monomer basis and are not convertible with the g/dL logic alone.
Transfusion and anaemia thresholds are defined in the unit of the guideline that sets them; convert the threshold or the patient value, never mix.

Frequently asked questions

How do I convert haemoglobin from g/dL to mmol/L?

Multiply by 0.6206. Example: 14.0 g/dL × 0.6206 = 8.7 mmol/L; 8.0 g/dL × 0.6206 = 5.0 mmol/L.

Which countries report haemoglobin in mmol/L?

Mainly the Netherlands; most other European countries use g/dL or g/L.

Why monomer and not tetramer?

Each globin chain carries one haem and binds one O₂, so the monomer is the functional unit for oxygen-binding calculations. Using the tetramer would give a value four times smaller for the same blood.

Evidence and guidelines

Primary source: AMA Manual of Style, 11th ed. (Oxford Academic) — Units of measure converter, Table 2: Selected laboratory tests and conversion factors.

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For healthcare professionals and medical students. These tools support, and do not replace, clinical judgement. Always check results against the original source and your local protocols.