MCV Level Checker

MedlinePlus’s blood count page prints “MCV: 80 to 100 femtoliter”, and StatPearls agrees: “a normal MCV ranges between 80 and 100 fL”, with under 80 called small and over 100 large. MedlinePlus’s newer RBC indices page prints 79 to 95 fL. Among the reasons MedlinePlus lists, a small MCV can point towards iron, and a large one towards vitamin B12 or folate.

How to use it

Find “MCV” (or “Mean corpuscular volume”) on your complete blood count and type the number — it is printed in fL, femtoliters, and usually looks like 88. You see where it sits against the 80–100 fL range and against MedlinePlus’s newer 79–95 fL, what MedlinePlus says a small, normal or large result may be a sign of, and the number your doctor will read beside it. Where the two ranges disagree, the page says so instead of choosing. If the number you typed is in the 20s or 30s and printed in pg or g/dL, it is the MCH or MCHC line, not the MCV — the page tells you.

What MCV measures, and the ranges

MedlinePlus: “MCV stands for mean corpuscular volume. An MCV blood test measures the average size of your red blood cells.” MedlinePlus’s blood count page lists it among the measurements a CBC provides, and its RBC indices page says the indices “are usually used to help diagnose the cause of anemia, a condition in which there are too few red blood cells”.

The ranges are not all the same. MedlinePlus’s Complete blood count page (review date 10/14/2024) prints “MCV: 80 to 100 femtoliter”. StatPearls’ chapter on Mean Corpuscular Volume (last update July 27, 2024): “On a complete blood count (CBC), the MCV measure is below 80 fL, whereas a normal MCV ranges between 80 and 100 fL.” and “Macrocytic anemia is characterized by an increased average RBC volume compared to normal levels, with an MCV measurement exceeding 100 fL on a CBC.” MedlinePlus’s RBC indices page (review date 2/27/2026) prints “MCV: 79 to 95 femtoliter”, and adds: “Normal value ranges may vary slightly among different labs.” Neither MedlinePlus page prints a range by age or sex, so this page does not invent one — for a child, the child’s report is the range.

How the number is made, in StatPearls’ words: “To calculate the MCV, the percent hematocrit is divided by the erythrocyte count, and the result is multiplied by 10”. So a report with a hematocrit and a red cell count already holds its MCV:

What a small or large MCV may point to

MedlinePlus’s MCV test page (last updated December 2, 2024) is careful first: “An MCV test alone cannot diagnose any disease.” Then: if your red blood cells are smaller than normal, it may be a sign of “Certain types of anemia, including iron deficiency anemia, the most common form of anemia. It happens when you don’t have enough iron in your body.” or “Thalassemia, which is a group of blood disorders that are inherited (passed down through families).” If they are larger than normal: “Pernicious anemia, which may be caused by: A lack of vitamin B12; A disease that affects your body’s ability to use vitamin B12, such as certain autoimmune diseases, celiac disease, or Crohn’s disease”; “Anemia caused by a lack of folic acid”; “Liver disease”. And “It’s also possible to have anemia with a normal MCV.” — after “A sudden loss of blood”, “Kidney failure” or “Aplastic anemia (uncommon)”.

The RBC indices page puts it in one line each: “MCV below normal. Microcytic anemia (may be due to low iron levels, lead poisoning, or thalassemia).” “MCV normal. Normocytic anemia (may be due to sudden blood loss, long-term diseases, kidney failure, aplastic anemia, or human-made heart valves).” “MCV above normal. Macrocytic anemia (may be due to low folate or vitamin B12 levels, or chemotherapy) or liver disease.” StatPearls adds that “non-megaloblastic anemia can result from hepatic insufficiency, chronic alcoholism, or a rare congenital disease known as Diamond-Blackfan anemia”.

The NIH’s Office of Dietary Supplements says the same from the nutrient side. On iron: “IDA is characterized by low hemoglobin concentrations and decreases in hematocrit (the proportion of red blood cells in blood by volume) and mean corpuscular volume (a measure of erythrocyte size)”, and “the resulting microcytic, hypochromic anemia is characterized by small red blood cells with low hemoglobin concentrations”. On folate: “Megaloblastic anemia, which is characterized by large, abnormally nucleated erythrocytes, is the primary clinical sign of folate or vitamin B12 deficiency”. On vitamin B12: “the hallmark megaloblastic anemia (characterized by large, abnormally nucleated red blood cells)”. Which of these, if any, applies to you is your doctor’s question, read with your other results — not a list’s.

Worked examples

• 88 fL (the page’s example) is inside both ranges.
• 76 fL is under both: red cells smaller than the range. The number ODS calls “the most efficient and cost-effective test for diagnosing iron deficiency” is serum ferritin — see the Ferritin Level Checker.
• 97 fL is inside 80–100 but above MedlinePlus’s newer 79–95 — where the two disagree, and the page says so.
• 104 fL is above both: red cells larger than the range. The Vitamin B12 Level Checker reads the vitamin ODS ties to large red cells.

Common mistakes

• Reading the MCV on its own. MedlinePlus: “An MCV test alone cannot diagnose any disease.” Your doctor reads it with your hemoglobin and hematocrit.
• Starting iron or vitamin B12 because of the MCV alone. A small MCV has more than one cause (thalassemia is inherited, not a shortage), and so does a large one; the tests your doctor orders next decide which.
• Taking a lot of folic acid and reading a normal MCV as “my B12 is fine”. NIH ODS: “Large amounts of folate can correct the megaloblastic anemia, but not the neurological damage, that can result from vitamin B12 deficiency.”
• Copying the wrong line. MCH (picograms) and MCHC (g/dL) sit just under MCV on the report; MedlinePlus prints “MCH: 26 to 33 picograms/cell (female); 27 to 33 picograms/cell (male)” and “MCHC: 32 to 36 grams hemoglobin/deciliter (g/dL) or 320 to 360 grams hemoglobin per liter (g/L)”.

Frequently asked questions

Read next

• How to Get Rid of Anemia? Best 4 Products
• Vitamin B12 as a Nootropic
• Vitamin B9
• Folic acid for Women & Men

This is not medical advice, and nothing here diagnoses or treats anything. It shows where a number sits against published ranges; what it means for you is a conversation with your doctor, who knows your lab, your other results and your history. Some links on this site are affiliate links: I buy what I review at full price, and a commission never changes a verdict.