MCV

What it is

MCV (mean corpuscular volume) is the average size of your red blood cells, calculated by the lab rather than measured cell by cell. It's one of the first things clinicians look at when hemoglobin is low, because average cell size helps point toward what's worth exploring — and it's read together with MCH, MCHC, and especially RDW. Its main limitation is that it's an average: if you have a mix of unusually small and unusually large cells, they can offset each other and MCV can land in the normal range, which is exactly why RDW (a measure of size variation) is looked at alongside it.

Typical range

Reference ranges vary between laboratories, and what is normal for you depends on your own history. Your own lab’s range is the one printed on your report.

Worth asking your clinician

• How does my MCV fit with my hemoglobin and RDW — do those numbers tell a consistent story together?
• Is this value a change from my previous results, or typical for me?
• Is my MCV something that needs follow-up, or is it fine in the context of the rest of my CBC?