What this calculator does
Neutrophils are the white cells that deal with bacterial infection, and a differential reports them as a percentage rather than a number. The absolute count converts that percentage into cells per microlitre, which is what actually determines infection risk.
The percentage alone can mislead badly. A white cell count of 2,000 with 58 per cent neutrophils gives an absolute count of 1,160 cells/µL, which is mild neutropenia, even though the percentage looks entirely normal.
The formula
Add the segmented and band neutrophil percentages, divide by 100 and multiply by the white blood cell count. Bands are immature neutrophils and are counted because they are functional.
| Term | Meaning |
|---|---|
| ANC | Absolute neutrophil count, in cells per microlitre. |
| Segs and bands | Mature and immature neutrophils, both counted toward the total. |
| Neutropenia | A low absolute count, graded as mild, moderate or severe. |
The inputs explained
| Field | What to enter |
|---|---|
| White blood cell count (cells/µL) | Total white blood cell count in cells per microlitre. |
| Segmented neutrophils (%) | Segmented (mature) neutrophils as a percentage of white cells. |
| Band neutrophils (%) | Band (immature) neutrophils as a percentage, added to the segmented figure. |
When to use it
Assessing infection risk
Risk depends on the absolute number of neutrophils, not on their share of the count.
Monitoring during chemotherapy
The count is tracked closely because treatment suppresses neutrophil production.
Reading a differential
Percentages need converting before they say anything about risk.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Why does the percentage alone mislead?
The same differential at three white cell counts.
| White cell count | ANC | Reading |
|---|---|---|
| 2,000 cells/µL | 1,160 cells/µL | 1,000 - 1,500: mild neutropenia |
| 7,000 cells/µL | 4,060 cells/µL | Within the typical adult range |
| 12,000 cells/µL | 6,960 cells/µL | Within the typical adult range |
Questions
Why include band neutrophils?
Because bands are immature but functional, so they contribute to fighting infection. A rising band count, sometimes called a left shift, can also indicate the marrow responding to an active infection.
What count is dangerous?
Below 500 cells/µL is severe neutropenia and carries a substantially raised risk of serious infection. Between 500 and 1,000 is moderate and 1,000 to 1,500 mild, though the clinical significance depends heavily on the cause.
What is febrile neutropenia?
A fever in someone with a low neutrophil count, which is treated as a medical emergency because the usual signs of infection may be blunted. Anyone told they are neutropenic should be given clear instructions on what to do if a fever develops.
Does ethnicity affect the normal range?
Yes. Benign ethnic neutropenia is a well-described variant in which the baseline count sits lower without any increase in infection risk, and applying the standard bands to those individuals can cause unnecessary concern.
For the red cell indices from the same count, see the MCH and MCHC calculator. For anemia screening, see the Mentzer index calculator.