MCV

What it measures

Reported in femtolitres (fL) everywhere, so there is no conversion to worry about. MCV is what separates the broad types of anaemia from one another — whether the red cells are unusually small, unusually large, or normal-sized — which is why it is often the first index a doctor reads after the haemoglobin itself.

Reading it in a different unit

This lab reports MCV in fl. Reports from other labs — especially ones using European or US-style formatting — sometimes use a different unit for the same measurement. The relationship between them:

um3 is the same value as fl under a different name — nothing to calculate, just a different label on the same number.

Unit conversions verified against published molar masses and LOINC definitions. This is not a diagnostic reference — the normal range for any test is set by the laboratory that ran it and printed on your report.

Why this matters for tracking a trend

A value plotted next to earlier results only tells you something if every point is on the same scale. Two readings of the same test from two different labs, in two different units, can look like a dramatic change when nothing about your actual result changed — only the unit did. Converting to one scale before comparing is what keeps a trend line honest.

LOINC code for this test: 787-2.