Hematocrit 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 Hematocrit, which differ for men and women:

Female: Optimal 37 – 44 % (0.37 – 0.44 L/L); sufficient 36 – 48 % (0.36 – 0.48 L/L); out of range below 36 or above 48 %.
Male: Optimal 40 – 46 % (0.4 – 0.46 L/L); sufficient 40 – 52 % (0.4 – 0.52 L/L); out of range below 40 or above 52 %.

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
%	Female	37 – 44	36 – 48	below 36 or above 48
%	Male	40 – 46	40 – 52	below 40 or above 52
L/L	Female	0.37 – 0.44	0.36 – 0.48	below 0.36 or above 0.48
L/L	Male	0.4 – 0.46	0.4 – 0.52	below 0.4 or above 0.52

What the evidence says

Sex-specific. The acceptable band ends where the British Society for Haematology says a persistently raised haematocrit should be investigated: above 0.48 in women and above 0.52 in men. The lower edges, 36% in women and 40% in men, are published laboratory limits; some laboratories set them 2 to 3 points lower. Where the client's sex is not recorded, the women's lower edge and the men's upper edge are used. Dehydration, altitude and smoking raise haematocrit. The narrower optimal band has no published source behind it.

Sources

CBC blood test — U.S. National Library of Medicine (MedlinePlus Medical Encyclopedia), 2024 · Government / public-health guidanceNormal haematocrit is 40% to 55% in men and 36% to 48% in women. The women's row is Sera's band exactly; the men's lower limit of 40% is the proposed edge.
A guideline for the diagnosis and management of polycythaemia vera. A British Society for Haematology Guideline — McMullin MF, Harrison CN, Ali S, et al. — British Society for Haematology (author manuscript in the Oxford University Research Archive; published in British Journal of Haematology), 2019 · Clinical guidelineA persistently raised venous haematocrit above 0.52 in men or 0.48 in women should be investigated. These are the upper edges of the sufficient band for each sex. Read in the author manuscript held by the Oxford University Research Archive.
Haematology reference ranges — Gloucestershire Hospitals NHS Foundation Trust, 2026 · Laboratory / reference-interval sourceAdult haematocrit 0.40 to 0.54 L/L in men and 0.37 to 0.47 L/L in women. Supports 0.40 as the men's lower limit.
Hematocrit — U.S. National Library of Medicine (MedlinePlus Medical Encyclopedia), 2026 · Government / public-health guidanceThe dedicated MedlinePlus page gives lower intervals: 37% to 48% in men and 34% to 43% in women (reviewed February 2026). Shows how far published limits differ; a men's lower limit of 37% would sit below the proposed 40%.
Full Blood Count (Haematology) — Liverpool Clinical Laboratories, Royal Liverpool University Hospital (NHS), 2013 · Laboratory / reference-interval sourceHaematocrit 0.38 to 0.51 L/L in men and 0.34 to 0.47 L/L in women. The page is undated; it is the laboratory's current page and says these ranges replaced the ones used before 2 April 2013.

What Hematocrit (HCT) measures

The share of your blood that is made up of red blood cells.

Low hematocrit points to anemia. Best watched alongside hemoglobin and ferritin.

Related blood cell health markers

See Hematocrit in the full list of biomarker ranges

This page is a reference for practitioners, not medical advice. Sera's bands are practitioner targets for structured review, not diagnostic thresholds, and Sera does not diagnose or recommend treatment. Read a result alongside the interval printed by the issuing laboratory and the client's history and symptoms. Range set: Sera Production, version 1.0, last reviewed November 9, 2026.