MCV calculator (hematocrit and red cell count)
The average size of your red blood cells. It helps show whether they run smaller or larger than usual. Type your results in the units on your report and it works out MCV as you type, in your browser.
AI-verified against cited sources. Awaiting expert reviewLast reviewed 2026-10-03Blood Cells
Type your results above, or fill in the example, to see MCV.
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Educational information, not medical advice. Blood Test Tracker doesn’t diagnose or treat, and it doesn’t replace your clinician. Talk with your clinician before changing medications, supplements or care.
How it’s worked out
The formula
MCV (fL) = Hematocrit (%) × 10 ÷ RBC (×10^6/µL). Most current analyzers measure MCV directly and calculate hematocrit from it, so this formula is only a fallback when a report omits MCV.
A worked example
Example numbers, not anyone’s real results, run through the same code as the calculator above.
| Hematocrit | 42 % |
|---|---|
| RBC | 4.7 ×10⁶/µL |
| MCV | 89.4 fL |
For an adult, this result is in the usual range.
What MCV tells you
Mean corpuscular volume (MCV) is the average size of your red blood cells, measured in femtoliters (fL). It is part of a routine complete blood count (CBC). Most blood-count machines measure it directly as cells pass through a small opening or a beam of light. Clinicians use it as an early clue to why your red cell count or hemoglobin might be low.
Size is a useful clue because different causes tend to push it in different directions. Smaller cells (low MCV) are most often linked to low iron or to thalassemia trait, an inherited difference in hemoglobin that usually causes no symptoms. Larger cells (high MCV) are linked to low vitamin B12 or folate, regular alcohol use, some medicines, and thyroid or liver conditions. MCV can sit outside the usual range even when hemoglobin is normal. Then it is usually something to mention at a routine visit.
Read the full page on MCV, with what a high or low result can mean.
Usual ranges
The ranges the result above is placed on. Your own lab’s printed range comes first if it gives one.
Sources
The equation
- MCV: Mean Corpuscular Volume (conversion and formula reference), UnitsLab
- Answer to Case on Crazy CBC Values (cold agglutinin disease), The Blood Project
12 more sources for the ranges and the explanation
- CBC with Differential: reference ranges (OHSU Lab Services test directory), Oregon Health & Science University Lab Services
- Evaluation of Microcytosis, American Family Physician (2010)
- Evaluation of Macrocytosis, American Family Physician (2009)
- Iron Deficiency Anemia: Evaluation and Management, American Family Physician (2013)
- Alpha- and Beta-thalassemia: Rapid Evidence Review, American Family Physician (2022)
- Sample report, CBC, Platelet, No Differential (test 028142), Labcorp (2020)
- Sample report, CBC With Differential/Platelet (test 005009), Labcorp
- CBC with Platelet Count and Automated Differential (ARUP test 0040003), reference intervals effective March 1, 2021, ARUP Laboratories (2021)
- RBC indices, MedlinePlus, National Library of Medicine
- Complete Blood Count with Differential (Parkview Laboratory test directory), Parkview Health Laboratory
- An epigenetic biomarker of aging for lifespan and healthspan, Aging (2018)
- Measurement of Red Cell Lifespan and Aging, Transfusion Medicine and Hemotherapy (2012)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. The calculator is version 1.0.0 of our code for this equation, tested against published examples. How we build and check these pages.