What the ANC measures
Neutrophils are the most common white blood cells and the body’s first defense against bacteria and fungi. A complete blood count (CBC) with differential reports them as a percentage of white cells. The absolute neutrophil count (ANC) turns that percentage into a number of cells:
ANC = WBC × (% segs + % bands) ÷ 100
With the WBC in × 10³/µL, multiply by 1,000 to get cells per microliter. Segs are mature, segmented neutrophils and bands are slightly younger ones; both count.
Worked example
A CBC shows a WBC of 6.0 × 10³/µL, 55% segmented neutrophils and 3% bands.
- Neutrophil share: 55 + 3 = 58%.
- ANC: 6,000 × 0.58 = 3,480 cells/µL, or 3.48 × 10⁹/L.
- This is within the usual adult range.
Neutropenia grades
| ANC (cells/µL) | Interpretation | Infection risk |
|---|---|---|
| 1,500 and above | normal for most adults | usual |
| 1,000 to 1,499 | mild neutropenia | slightly increased |
| 500 to 999 | moderate neutropenia | increased |
| below 500 | severe neutropenia | high |
When it matters most
- Chemotherapy: the ANC usually reaches its lowest point 7 to 14 days after a dose. Many treatments are delayed when the ANC is below 1,000 to 1,500.
- Fever with a low ANC: a temperature of 100.4 °F (38 °C) or higher with an ANC below 500 is called febrile neutropenia and needs urgent care.
- Medications: some drugs, such as clozapine, require regular ANC monitoring.
A normal variant
Many people of African, Middle Eastern or West Indian ancestry have a lower ANC, often between 1,000 and 1,500, with no increase in infections. This is now linked to the Duffy-null blood group, and some labs report a separate reference range for it.
Other causes of a low or high count
A low ANC can come from viral infections, vitamin B12 or folate deficiency, autoimmune disease, medications or bone marrow problems. A high ANC (neutrophilia) is common with bacterial infections, stress, smoking, steroids and pregnancy. Your doctor interprets the result with the rest of the blood count.
This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.