Hemoglobin Normal Range

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Hemoglobin is the iron-containing protein in red blood cells that carries oxygen from the lungs to the rest of the body, and a hemoglobin test measures how much of it is present in a fixed volume of blood. Two different sets of published figures are quoted for it. Laboratory reference ranges describe what is typical in healthy people tested by a particular method. World Health Organization cutoffs define anaemia. They answer different questions, and this page sets out both. Values also shift with sex, age, pregnancy and altitude, so the range printed on your own report is the one that counts.

What hemoglobin is and what the test measures

Hemoglobin is the iron-containing protein packed inside red blood cells. It binds oxygen in the lungs, carries it through the bloodstream, and releases it where tissues need it. Many Indian laboratories print it as Haemoglobin (Hb), the British spelling of the same word, on a complete blood count report.

The test reports a concentration — how much hemoglobin sits in a fixed volume of blood. Reports in India commonly use grams per decilitre (g/dL). Global guidelines and many hospital laboratories use grams per litre (g/L). The two say the same thing: divide a g/L figure by ten to get g/dL, so 120 g/L and 12.0 g/dL are the identical result written two ways.

A hemoglobin value below the expected level is what doctors call anaemia. A value above it has its own separate list of possible explanations. Neither number explains itself. Both are read alongside the rest of the blood count, the person’s history, and often a repeat sample.

Laboratory reference ranges for hemoglobin

A reference range is not a target. It describes the spread of values found in most healthy people tested by a particular method, and it is usually set so that a small number of perfectly healthy people fall just outside it. MedlinePlus, published by the US National Library of Medicine, lists these hemoglobin reference ranges:

• Adult male: 13.8 to 17.2 g/dL (138 to 172 g/L)
• Adult female: 12.1 to 15.1 g/dL (121 to 151 g/L)
• Newborn: 14 to 24 g/dL (140 to 240 g/L)
• Infant: 9.5 to 14 g/dL (95 to 140 g/L)

MedlinePlus states plainly that normal value ranges may vary slightly among different laboratories, and that some laboratories use different measurements or test different samples. That sentence matters as much as the numbers above it.

WHO hemoglobin cutoffs that define anaemia

The World Health Organization publishes a different set of figures for a different purpose. Its 2024 guideline sets the hemoglobin cutoffs used to define anaemia in individuals and populations. They are based on the 5th percentile and are stated in g/L:

• Children 6 to 23 months: anaemia below 105 g/L (10.5 g/dL)
• Children 24 to 59 months: anaemia below 110 g/L (11.0 g/dL)
• Children 5 to 11 years: anaemia below 115 g/L (11.5 g/dL)
• Boys 12 to 14 years: anaemia below 120 g/L (12.0 g/dL)
• Non-pregnant girls 12 to 14 years: anaemia below 120 g/L (12.0 g/dL)
• Non-pregnant women 15 to 65 years: anaemia below 120 g/L (12.0 g/dL)
• Men 15 to 65 years: anaemia below 130 g/L (13.0 g/dL)
• Pregnancy, first trimester: anaemia below 110 g/L (11.0 g/dL)
• Pregnancy, second trimester: anaemia below 105 g/L (10.5 g/dL)
• Pregnancy, third trimester: anaemia below 110 g/L (11.0 g/dL)

The g/dL figures in brackets are the same values converted, since one g/dL equals ten g/L.

Two sets of numbers, two different questions

This is why two credible sources can quote different numbers without either being wrong. It is also why a printed flag such as low on a report is a prompt for a conversation, not a conclusion. Which framework applies to a particular person, whether the result fits the symptoms, and whether anything needs to be done are decisions for the treating doctor.

Children and newborns: the range moves fast

Hemoglobin is high at birth, falls over the first months of life, then climbs slowly through childhood. A single childhood range would be misleading, so paediatric laboratories band it by age. North Bristol NHS Trust publishes these reference ranges for children, in g/L:

• Birth: 140 to 240
• 2 weeks: 134 to 198
• 4 weeks: 134 to 198
• 2 to 6 months: 94 to 130
• 6 months to 1 year: 111 to 141
• 1 to 6 years: 115 to 140

The dip between two and six months is expected physiology, not a fault in the sample. WHO describes its own child cutoffs as a gradual increase from 105 g/L at 23 months, to 110 g/L at 59 months, and to 115 g/L from five years of age — which means a birthday alone can change which cutoff applies to the same child. This is one reason children’s reports should be read against a paediatric range rather than an adult one.

Why hemoglobin differs by sex, age, pregnancy and altitude

• Sex: adult men are given both a higher reference range and a higher WHO anaemia cutoff than women. Regular menstrual blood loss and hormonal differences in red cell production are part of the explanation.
• Age: newborn values are the highest a person will ever have, and infant values are among the lowest. Ranges are therefore banded by age rather than pooled into one figure.
• Pregnancy: plasma volume expands faster than red cell mass, so the concentration falls even when the total amount of hemoglobin has not. WHO sets a lower cutoff in the second trimester than in the first or third.
• Altitude: MedlinePlus notes that a hemoglobin level will increase for several weeks at a higher altitude, because less oxygen in the air prompts the body to make more red cells. WHO records that a technical meeting considered adjusting hemoglobin cutoffs for elevation above sea level and for smoking.

Sample handling, hydration and the analyser used can also shift a figure slightly. That is one reason doctors often repeat a borderline hemoglobin rather than act on a single reading.

The range printed on your own report is the one that governs

Every laboratory validates its reference intervals against its own analyser, its reagents and the population it serves. That is why the range printed beside your result may not match the figures above, and why it should be read first.

Reference ranges vary by laboratory, method, age, sex, pregnancy and clinical context. A result slightly outside a printed range is not automatically a disease, and a result inside it does not rule one out. Interpretation belongs to the treating doctor, who has the symptoms, the examination, the medicines being taken and the rest of the blood count in front of them — none of which appear on this page.

If you are comparing an older report with a newer one, check that both used the same units and, where possible, the same laboratory. Reading a g/dL figure against a g/L figure is an easy mistake to make, and it can make two ordinary results look very different from each other.

Thyroid function is another test where the printed range does the work. The same logic is set out in our guide to TSH, T3 and T4 reference ranges.

When to seek medical help quickly

Outside an emergency, the sensible next step after an unexpected hemoglobin result is an appointment. Take the full report rather than a single figure, along with any earlier reports, so the doctor can see the direction of travel as well as the number.

Frequently asked questions

Sources

MedlinePlus Medical Encyclopedia, US National Library of Medicine (NIH) — Hemoglobin test · World Health Organization — Guideline on haemoglobin cutoffs to define anaemia in individuals and populations (2024), cutoff table · World Health Organization — Guideline on haemoglobin cutoffs to define anaemia in individuals and populations (2024), guideline text · North Bristol NHS Trust, Department of Haematology — Children's Reference Ranges for Routine Full Blood Count

Last checked 2 September 2026. How we write and check these pages: editorial policy.