Red cell indices describe the size and haemoglobin content of red blood cells and are the first step in working out the cause of anaemia: small cells suggest iron deficiency or thalassaemia; large cells suggest B12 or folate deficiency, alcohol or liver disease.
How to use the RBC Indices Calculator
- Haemoglobin
- Haematocrit
- Red blood cell count
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter haemoglobin, haematocrit and red cell count from the same blood count.
Inputs explained
| Field | What to enter |
|---|---|
| Haemoglobin | Units: g/dL, g/L, mmol/L |
| Haematocrit | In % |
| Red blood cell count | In ×10¹²/L |
What each result means
- MCV = [Haematocrit]×10÷[Red blood cell count]
- MCH = [Haemoglobin]×10÷[Red blood cell count]
- MCHC = [Haemoglobin]÷[Haematocrit]×100
- Mentzer index = [MCV]÷[Red blood cell count]
Example values
How the main result changes when Haemoglobin changes and everything else stays at the example values above:
| Haemoglobin (g/dL) | MCV (fL) |
|---|---|
| 6 | 86 |
| 9 | 86 |
| 12 | 86 |
| 15 | 86 |
| 18 | 86 |
| 24 | 86 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
MCV (fL) = Hct (%) × 10 ÷ RBC (×10¹²/L)
MCH (pg) = Hb (g/dL) × 10 ÷ RBC
MCHC (g/dL) = Hb ÷ Hct × 100
Worked example
Inputs — Haemoglobin: 12 g/dL; Haematocrit: 36 %; Red blood cell count: 4.2 ×10¹²/L.
Results — MCV = 86 fL; MCH = 28.6 pg; MCHC = 33.3 g/dL; Mentzer index = 20.4.
Key terms
- MCV
- Mean corpuscular volume.
- MCH
- Mean corpuscular haemoglobin.
- MCHC
- Mean corpuscular haemoglobin concentration.
Frequently asked questions
What is a normal MCV?
About 80–100 fL.
What does a low MCV mean?
Small red cells, most often from iron deficiency or thalassaemia trait.
What is MCHC?
The average concentration of haemoglobin in red cells; normal 32–36 g/dL.