Absolute lymphocyte count
Estimates the absolute lymphocyte count from the total white cell count and the lymphocyte percentage.
When to use
When the differential gives only the lymphocyte percentage and the absolute value is needed, for example to assess lymphopenia.
Pearls and pitfalls
- It is the percentage multiplied by the total white cell count, not a value read directly from the report.
- The laboratory reference range in the published case was 1.0 to 4.0 ×10³/µL.
- A normal percentage with a low total count can give a low absolute count, and the reverse also happens.
- Check whether the white cell count is in cells per µL or in ×10³/µL before converting.
Fill in the fields to see the result.
Formula
Absolute lymphocytes (×10³/µL) = white cells (/µL) × lymphocyte percentage ÷ 100 ÷ 1000.
Evidence
Calculation derived from the differential count, with a worked example and reference range published in a 2026 case report.
References
- Culture-Confirmed Multilobar Cavitary Pulmonary Tuberculosis Despite a Negative QuantiFERON-TB Gold Assay in an Immunocompetent Young Adult. Cureus. 2026. doi:10.7759/cureus.112415
Frequently asked questions
What is Absolute lymphocyte count?
Estimates the absolute lymphocyte count from the total white cell count and the lymphocyte percentage. When the differential gives only the lymphocyte percentage and the absolute value is needed, for example to assess lymphopenia.
How is the result calculated?
Absolute lymphocytes (×10³/µL) = white cells (/µL) × lymphocyte percentage ÷ 100 ÷ 1000.
How should the result be interpreted?
Calculation derived from the differential count, with a worked example and reference range published in a 2026 case report.
What are the sources?
Culture-Confirmed Multilobar Cavitary Pulmonary Tuberculosis Despite a Negative QuantiFERON-TB Gold Assay in an Immunocompetent Young Adult. Cureus. 2026.