Monocyte count optimal range and reference range

Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026

Sera's bands for Monocyte count:

  • Optimal 0.2 – 0.6 ×10⁹/L (0.2 – 0.6 ×10³/μL); sufficient 0.1 – 0.8 ×10⁹/L (0.1 – 0.8 ×10³/μL); out of range below 0.1 or above 0.8 ×10⁹/L.

Evidence grade: Published reference interval. A band that primarily reflects a published adult laboratory or population reference interval. It is not necessarily applicable to every assay or laboratory.

At Sera's last range review a change to this band was proposed and held, because the evidence for it was thin, so the band is unchanged. The note below says where it matches published intervals and where it does not.

All units

UnitOptimalSufficientOut of range
×10⁹/L0.2 – 0.60.1 – 0.8below 0.1 or above 0.8
×10³/μL0.2 – 0.60.1 – 0.8below 0.1 or above 0.8
K/μL0.2 – 0.60.1 – 0.8below 0.1 or above 0.8
/mm³200 – 600100 – 800below 100 or above 800
x E9/L0.2 – 0.60.1 – 0.8below 0.1 or above 0.8

What the evidence says

The acceptable band's upper edge of 0.8 ×10⁹/L is the adult upper limit at two NHS laboratories; others use 1.0. Its lower edge of 0.1 matches no source: the NHS laboratories checked use 0.2. The optimal band of 0.2 to 0.6 has no outcome evidence behind it.

Sources

  • Haematology reference ranges — Gloucestershire Hospitals NHS Foundation Trust, 2026 · Laboratory / reference-interval sourceAdult monocytes 0.2 to 0.8 ×10⁹/L. Matches Sera's sufficient upper edge of 0.8; the lower limit is 0.2, not Sera's 0.1.
  • Full blood count (FBC) — Black Country Pathology Services (NHS), 2026 · Laboratory / reference-interval sourceAdult monocytes 0.2 to 0.8 ×10⁹/L. Matches Sera's sufficient upper edge of 0.8; the lower limit is 0.2, not Sera's 0.1. The page shows no review date; 2026 is the footer year.
  • White Blood Count — North Bristol NHS Trust, Severn Pathology, 2026 · Laboratory / reference-interval sourceAdult monocytes 0.2 to 1.0 ×10⁹/L. Same lower limit of 0.2; a wider upper limit than Sera's 0.8. The page shows no review date; 2026 is the footer year.
  • FBC — University Hospitals Sussex NHS Foundation Trust, Pathology, 2022 · Laboratory / reference-interval sourceAdult monocytes 0.2 to 1.0 ×10⁹/L. Same lower limit of 0.2; a wider upper limit than Sera's 0.8.
  • AUTO DIFF (test catalog entry) — MHCC Laboratory, test catalog powered by Mayo Clinic Laboratories, 2026 · Laboratory / reference-interval sourceAdult absolute monocytes 0.05 to 0.6 ×10³/μL. Its upper limit equals Sera's optimal upper edge of 0.6; its lower limit of 0.05 is below every Sera edge. The page shows no review date; 2026 is the copyright year.

What Monocytes # measures

The number of monocytes, large white blood cells that fight long-term infections.

High levels can point to ongoing inflammation or a long-term infection.

Related blood cell health markers

See Monocyte count in the full list of biomarker ranges

About the author

Alina Radu is the founder of Sera and a software engineer. The idea started with her own Hashimoto's tests, scattered across years without the big picture. She is not a clinician: these ranges are compiled from the published sources linked on each page, with every source named. Alina Radu on LinkedIn

This page is a reference for practitioners, not medical advice. Sera's bands are practitioner targets for structured review, not diagnostic thresholds, and Sera does not diagnose or recommend treatment. Read a result alongside the interval printed by the issuing laboratory and the client's history and symptoms. Range set: Sera Production, version 1.0, last reviewed November 9, 2026.