How is the absolute neutrophil count (ANC) calculated?

• A. ANC = WBC × (percentage of neutrophils + bands); typically expressed in x10^9/L.
• B. ANC = WBC × neutrophils%
• C. ANC = RBC × (neutrophils% + bands%)
• D. ANC = WBC × (lymphocytes%)

Answer: (A)

The essential idea is that the absolute neutrophil count shows how many neutrophils are in a given volume of blood, and neutrophils include both mature cells (segmented) and immature cells (bands). To get this, you take the total white blood cell count and multiply it by the fraction that are neutrophils, with both segmented neutrophils and bands combined. That’s why the formula is WBC × (neutrophil percentage + bands percentage), giving the result in units like x10^9/L.

Example: if WBC is 6.0 x10^9/L and neutrophils are 55% with 5% bands, ANC = 6.0 × (0.55 + 0.05) = 6.0 × 0.60 = 3.6 x10^9/L. The key is including both neutrophils and bands in the neutrophil portion. The other options omit bands, use the wrong cell type, or rely on a different calculation, which doesn’t reflect the neutrophil portion of the WBC differential.