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About this tool
Convert haemoglobin between g/dL, g/L and mmol/L, and compare the result against WHO anaemia thresholds by age and sex.
The Haemoglobin Unit Converter changes a haemoglobin result between g/dL, g/L and mmol/L, using the exact 10× relationship between g/dL and g/L and the SI factor of 0.6206 mmol/L per g/dL, which comes from the 16,114.5 g/mol molar mass of the iron-carrying haemoglobin monomer. It then compares the value with the World Health Organization anaemia thresholds for the relevant age, sex and pregnancy group, and applies the WHO altitude adjustment above 1,000 metres.
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Enter the values you already know.
Fine-tune the options to match your scenario.
Read the result and use it in your planning or reporting.
g/dL, g/L and mmol/L are shown together, so you never have to chain two conversions.
Men, non-pregnant women, pregnant women and three childhood bands each have their own WHO cut-off.
Applies the published WHO adjustment table from 1,000 metres up, interpolating between listed elevations.
Multiply by 0.6206. So 14 g/dL is 8.7 mmol/L and 12 g/dL is 7.45 mmol/L. Divide by 0.6206 to convert mmol/L back to g/dL. The factor is based on the haemoglobin monomer, which is why it differs from the factors used for other blood tests.
Using WHO thresholds at sea level: below 13.0 g/dL (130 g/L) for men aged 15 and over, below 12.0 g/dL (120 g/L) for non-pregnant women aged 15 and over, and below 11.0 g/dL (110 g/L) in pregnancy and in children aged 6 to 59 months. Individual laboratory reference intervals may differ slightly.
No — g/L is exactly ten times the g/dL number, because a decilitre is a tenth of a litre. A haemoglobin of 13.5 g/dL is 135 g/L. Mixing the two is the most common misreading of a full blood count from another country.
Lower oxygen pressure at height stimulates red cell production, so healthy people living at altitude run higher haemoglobin. WHO therefore subtracts a published amount before applying the anaemia thresholds — about 0.2 g/dL at 1,000 metres, 1.3 g/dL at 2,500 metres and 3.5 g/dL at 4,000 metres. Without that adjustment, anaemia at altitude is missed.
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