Hemoglobin optimal range and reference range
Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026
Sera's bands for Hemoglobin, which differ for men and women:
- Female: Optimal 13.5 – 14.5 g/dL (135 – 145 g/L); sufficient 12 – 16 g/dL (120 – 160 g/L); out of range below 12 or above 16 g/dL.
- Male: Optimal 14 – 15.5 g/dL (140 – 155 g/L); sufficient 13 – 18 g/dL (130 – 180 g/L); out of range below 13 or above 18 g/dL.
Evidence grade: Established clinical threshold. A band edge that corresponds to a recognised diagnostic, risk or treatment threshold from a major clinical guideline or public-health body.
All units
| Unit | Applies to | Optimal | Sufficient | Out of range |
|---|---|---|---|---|
| g/dL | Female | 13.5 – 14.5 | 12 – 16 | below 12 or above 16 |
| g/dL | Male | 14 – 15.5 | 13 – 18 | below 13 or above 18 |
| g/L | Female | 135 – 145 | 120 – 160 | below 120 or above 160 |
| g/L | Male | 140 – 155 | 130 – 180 | below 130 or above 180 |
| mmol/L | Female | 8.4 – 9 | 7.4 – 9.9 | below 7.4 or above 9.9 |
| mmol/L | Male | 8.7 – 9.6 | 8.1 – 11.2 | below 8.1 or above 11.2 |
What the evidence says
Sex-specific. The acceptable band starts where the WHO defines anaemia: below 12 g/dL (120 g/L) in non-pregnant women and below 13 g/dL (130 g/L) in men. The upper edges, 16 g/dL in women and 18 g/dL in men, are published laboratory limits; laboratories differ by up to 1 g/dL here. Where the client's sex is not recorded, the women's lower edge and the men's upper edge are used. Altitude, smoking and plasma volume all shift haemoglobin independently of iron status. The narrower optimal band has no published source behind it.
Sources
- British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults — Snook J, Bhala N, Beales ILP, et al. — Gut, 2021 · Clinical guidelineStates the WHO definition of anaemia: haemoglobin below 130 g/L in men and below 120 g/L in non-pregnant women. This is the lower edge of the sufficient band for each sex. Full text read through Europe PMC (PMC8515119).
- CBC blood test — U.S. National Library of Medicine (MedlinePlus Medical Encyclopedia), 2024 · Government / public-health guidanceNormal haemoglobin is 13 to 18 g/dL in men and 12 to 16 g/dL in women. The women's row is Sera's band exactly; the men's row is the proposed band.
- Haematology reference ranges — Gloucestershire Hospitals NHS Foundation Trust, 2026 · Laboratory / reference-interval sourceAdult haemoglobin 130 to 180 g/L in men and 115 to 165 g/L in women. Supports the men's 13 to 18 g/dL; its women's interval sits 0.5 g/dL either side of Sera's.
- Full Blood Count (Haematology) — Liverpool Clinical Laboratories, Royal Liverpool University Hospital (NHS), 2013 · Laboratory / reference-interval sourceHaemoglobin 130 to 180 g/L in men and 120 to 160 g/L in women, the same numbers as the proposed bands. The page is undated; it is the laboratory's current page and says these ranges replaced the ones used before 2 April 2013.
- Hemoglobin — U.S. National Library of Medicine (MedlinePlus Medical Encyclopedia), 2026 · Government / public-health guidanceA narrower adult interval on the dedicated MedlinePlus page: 13.8 to 17.2 g/dL in men and 12.1 to 15.1 g/dL in women (reviewed February 2026). Shows that published upper limits for women range from 15.1 to 16.5.
- Haemoglobin thresholds to define anaemia from age 6 months to 65 years: estimates from international data sources — Braat S, Fielding KL, Han J, et al. — The Lancet Haematology, 2024 · Peer-reviewed publicationPooled healthy reference samples from eight countries, including the USA, England, Canada and the Netherlands: the fifth centile of haemoglobin was 119.7 g/L in non-pregnant women and 134.9 g/L in men aged 18 to 65. Confirms 120 g/L for women and suggests the men's threshold could be 135 rather than 130.
What Hemoglobin (HGB) measures
The protein in red blood cells that carries oxygen.
Low hemoglobin causes fatigue and makes exercise harder. A common cause of unexplained tiredness.
Related blood cell health markers
- RBC # (Red Blood Cell Count)
- Hematocrit (HCT)
- Mean Corpuscular Volume (MCV)
- Mean Corpuscular Hemoglobin (MCH)
- Mean Corpuscular Hemoglobin Concentration (MCHC)
- RDW (Red Cell Distribution Width)
- WBC # (White Blood Cell Count)
- Neutrophils #
- Lymphocytes #
- Monocytes #
- Eosinophils #
- Basophils #
- Neutrophils %
- Lymphocytes %
- Monocytes %
- Eosinophils %
- Basophils %
- Immature Granulocytes %
- Platelets (Thrombocytes)
- PCT (Plateletcrit)
- Reticulocytes (Absolute)
- Reticulocytes (%)
- Ferritin
- Iron (Serum)
- Transferrin
- TIBC (Total Iron Binding Capacity)
- Transferrin Saturation
- UIBC (Unsaturated Iron Binding Capacity)