Reticulocyte Production Index (RPI) Calculator

Medical Calculator – SonDoctor.com

Reticulocyte Production Index (RPI) Calculator

Corrected Reticulocyte Count (CRC) =
Reticulocyte (%) x (Hct / 45) or (Hb / 15)

Reticulocyte Production Index (RPI) =
Corrected Reticulocyte Count / Maturation time

Maturation time :
Hct ≤ 15 : 2.5
16 < Hct ≤ 25 : 2
26 < Hct ≤ 35 : 1.5
35 < Hct : 1

Reticulocyte (%) :
Hct (%) :

※ This calculator assumes normal adult Hct of 45%.

Reticulocyte : The amount of reticulocytes in peripheral blood reflects the hematopoietic status.
Corrected Reticulocyte Count : When Hb decreases, reticulocytes appear relatively increased, and the Corrected Reticulocyte Count corrects for this.
Reticulocyte Production Index (RPI) : When hematopoiesis increases, erythroid cells are released into peripheral blood in an immature state, prolonging the period they exist as reticulocytes. The Reticulocyte Production Index corrects for this.
- In anemic patients, an RPI of 2.5 or higher suggests hemolysis or bleeding. (However, an RPI below 2.5 does not exclude hemolysis and bleeding.)