The absolute neutrophil count (ANC) can be calculated from a routine CBC by:

• A. Subtracting the sum of segmented and band neutrophil percentages on the differential count from the white cell count
• B. Multiplying the white cell count with the sum of segmented and band neutrophil percentages on the differential count
• C. Dividing the white cell count by the sum of segmented and band neutrophil percentages on the differential count
• D. Adding the white cell count to the sum of segmented and band neutrophil percentages on the differential count

Answer: (C)

Absolute neutrophil count measures how many neutrophil cells are present in a given volume of blood. It’s obtained by combining the total white cell count with the fraction of those cells that are neutrophils, specifically the sum of segmented neutrophils and bands.

Compute it by multiplying the total white cell count by the proportion of neutrophils. If the differential gives percentages, convert to a decimal by dividing by 100, so ANC = WBC × (segmented neutrophil% + band neutrophil%) / 100. If the differential already lists neutrophil fractions as decimals, you can simply multiply WBC by that sum.

This approach avoids the incorrect results from subtracting or adding the percentages to the white count or dividing the white count by the neutrophil percentage.