This tool provides multiple calculations:

• Absolute reticulocyte count: The number of reticulocytes in a volume of blood. Use when a direct measure of red blood cell production is needed, such as in early treatment response or non-anemic conditions with altered RBC turnover.
• Corrected reticulocyte percentage/reticulocyte index (RI): Adjusts the reticulocyte percentage to account for the degree of anemia. Can be appropriate as a quick assessment of marrow response in mild to moderate anemia, where adjusting for maturation time may not be necessary.
• Reticulocyte production index (RPI): Adjusts the reticulocyte index to account for the longer maturation time of reticulocytes released prematurely from the bone marrow. Useful in moderate to severe anemia, where reticulocytes are often released early.