Corrected Reticulocyte Count
Calculate the Corrected Reticulocyte Count (CRC) and Reticulocyte Production Index (RPI) to assess bone marrow response to anemia.
Patient Values
%
%
%
Standard adult reference is 45. Adjust if your lab uses a different value.
Enter patient values and click Calculate to see results
Corrected Reticulocyte Count (CRC)
--
%
CRC = Retic% × (Patient Hct / Normal Hct)
Maturation Factor
--
Reticulocyte Production Index (RPI)
--
RPI = CRC / Maturation Factor
Formula Breakdown
For educational use only. Not a substitute for clinical judgment.
Summary
Calculate the Corrected Reticulocyte Count (CRC) and Reticulocyte Production Index (RPI) to assess bone marrow response to anemia.
How it works
- Enter the patient reticulocyte percentage, patient hematocrit, and optional normal hematocrit (default 45%). CRC = Retic% x (Patient Hct / Normal Hct). The maturation factor is determined by the patient hematocrit tier, and RPI = CRC / Maturation Factor. An RPI below 2 suggests inadequate marrow response; an RPI of 2 or above suggests adequate response (hemolysis or blood loss).
Use cases
- Differentiate hypoproliferative from hyperproliferative anemia at the bedside.
- Assess bone marrow response following treatment for iron deficiency or B12/folate deficiency anemia.
- Evaluate suspected hemolytic anemia or acute blood loss.
- Screen for impaired erythropoiesis in chronic disease.
Frequently Asked Questions
Last updated: 2026-06-11 ·
Reviewed by Nham Vu