Blood
Hematocrit (Hct)
Also known as: PCV, Packed Cell Volume
CONVERT & COMPARE
%
=
0.435
L/L
Reference ranges by source
Published adult intervals: 12, from 6 named sources, shown in %.
SOURCE
SEX
AGE
RANGE
VISUAL
CITE
J
JSCC / JAMT Japan
Male
≥18y
40.7 – 50.1 %
J
JSCC / JAMT Japan
Female
≥18y
35.1 – 44.4 %
T
Turkey Nationwide Reference Intervals
Male
≥18y
39.2 – 52.2 %
T
Turkey Nationwide Reference Intervals
Female
≥18y
33.7 – 46.1 %
J
JSCC / JAMT Japan
Male · ≥18y
40.7 – 50.1 %
J
JSCC / JAMT Japan
Female · ≥18y
35.1 – 44.4 %
T
Turkey Nationwide Reference Intervals
Male · ≥18y
39.2 – 52.2 %
T
Turkey Nationwide Reference Intervals
Female · ≥18y
33.7 – 46.1 %
Ages 0–17 (CALIPER)
5 age- and sex-stratified entries from the Canadian Laboratory Initiative on Pediatric Reference Intervals.
SOURCE
SEX
AGE
RANGE
VISUAL
CITE
About Hematocrit (Hct)
A hematocrit test is a blood test that measures the amount (percent) of your blood that is made up of red blood cells. Red blood cells carry oxygen from your lungs to the rest of your body. The other parts of your blood include white blood cells (to help fight infection and other diseases), platelets (to help make blood clots to stop bleeding), and a liquid called plasma.
Hematocrit levels that are too high or too low can be a sign of a blood disorder, dehydration, or other medical conditions that affect your blood.
Your health care provider may order a hematocrit test as part of your routine checkup or to monitor your health if you are being treated for cancer or have an ongoing health condition. Your provider may also order this test if you have symptoms of a red blood cell disorder, such as anemia or polycythemia.
Main source: MedlinePlus ↗
Useful for
A hematocrit (HCT) test is often part of a complete blood count (CBC), a common blood test that measures the number and type of cells in your blood.
It is used to check your general health.
It may also be used to monitor or help diagnose blood disorders. These could include anemia, a condition in which you don't have enough red blood cells, and polycythemia (erythrocytosis), an uncommon disorder in which you have too many red blood cells and your blood becomes too thick.
It can help track how your bone marrow is recovering during treatments such as chemotherapy or radiation, since these can lower your red blood cell count.
It is often reviewed alongside red cell size measurements (such as MCV and RDW) to help narrow down the type of anemia you may have.
Main source: MedlinePlus ↗
Interpretation
Your hematocrit test results are reported as a number. That number is the percentage of your blood that's made up of red blood cells. For example, if your hematocrit test result is 42, it means that 42% of your blood is red blood cells, and the rest is made up of white blood cells, platelets, and blood plasma.
Normal hematocrit levels will vary, depending on your sex, age, whether or not you smoke, and the altitude where you live. Ask your provider what your hematocrit level should be, and what a higher- or lower-than-normal result might mean for you.
A low hematocrit may point to anemia, recent blood loss, certain bone marrow problems, kidney disease, or fluid overload. A high hematocrit can be seen with dehydration, smoking, lung or heart disease, living at high altitude, or polycythemia. Your provider will look at your hematocrit together with the rest of your blood count and your symptoms to figure out what's going on.
For general wellness information only. Talk to a clinician about your specific results.
Main source: MedlinePlus ↗
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Related biomarkers
More tests in the blood category.
Sources
M
Mayo Clinic Laboratories
L
Labcorp
N
Nordic Reference Interval Project
U
UK Pathology Harmony
J
JSCC / JAMT Japan
T
Turkey Nationwide Reference Intervals
C
CALIPER: Canadian Pediatric Reference Intervals
Last updated 2026-05-02
This page presents source-specific reference data and sourced explanations. For general wellness information only. This is not medical advice. For diagnosis or treatment of any condition, talk to a qualified clinician.