Immunology & cytokines

CD4 count unit converter

CD4 T helper cells in the blood

Also known as: CD4+ T-cell count, CD4 T cells, T4 count, Helper T cells, T-Helferzellen, CD4-Zellen

Converter

Enter a value in any unit and all other units fill in.

10⁹/L /µL

Worked example

1 10⁹/L (middle of the reference range) = 1 000 /µL

Conversion formulas

/µL	/µL = 10⁹/L × 1000	10⁹/L = /µL × 0.001

Good to know

The CD4 count is the number of CD4 T helper cells in the blood. It is reported as cells per µL (= cells/mm³) or as ×10⁹/L.

1 cell/µL = 1 cell/mm³; 500 cells/µL equals 0.5 ×10⁹/L.
The percentage of CD4 cells among lymphocytes is a different value from the absolute count.

Reference range

Unit	Adults
10⁹/L	0.5 – 1.5
/µL	500 – 1500

Source: MedlinePlus (NLM): T-cell count · Last reviewed: 2026-10-19

Note from the source: In adults 500-1,500 cells/mm³ (0.50-1.50 ×10⁹/L); 1 cell/mm³ = 1 cell/µL (MedlinePlus)

Frequently asked questions

How do I convert CD4 count from 10⁹/L to /µL?

/µL = 10⁹/L × 1000. In the other direction: 10⁹/L = /µL × 0.001.

What is the reference range of CD4 count?

For adults the range is 0.5 – 1.5 10⁹/L (MedlinePlus (NLM): T-cell count). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for CD4 count?

Common units are 10⁹/L, /µL.