Hct (hematocrit)

Hct (hematocrit): Abbreviation for hematocrit.

The hematocrit is the proportion, by volume, of the blood that consists of red blood cells. The hematocrit (hct) is expressed as a percentage.

For example, an hematocrit of 25% means that there are 25 milliliters of red blood cells in 100 milliliters of blood. A quarter of the blood consists of red cells.

The normal ranges for hematocrit are dependant on age and, after adolescence, the sex of the individual. The normal ranges are:

  • Newborns: 55-68%
  • One (1) week of age: 47-65%
  • One (1) month of age: 37-49%
  • Three (3) months of age: 30-36%
  • One (1) year of age: 29-41%
  • Ten (10) years of age: 36-40%
  • Adult males: 42-54%
  • Adult women: 38-46%

These values may vary slightly between laboratories.