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🩸 Mentzer Index Calculator

UseFirst-pass discrimination of microcytic anaemia.

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SourceMentzer WC. Lancet 1973

Runs locally in your browser (no PHI uploaded). For licensed clinicians — not a substitute for clinical judgement.
Stored on this device for revisit reminders

This-shift next steps

After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.

Scene next step
📋hematologyOpen scene pack →
Related scores
Matching pathway
🧭febrile_neutropeniaOpen pathway →
Score + version; reference only — not a substitute for care · no HIS write

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Methodology · worked example, guidelines & full notes
Clinical takeaway

Thalassaemia trait: high RBC, low MCV → low index.

When to use

First-pass discrimination of microcytic anaemia.

How it works

Mentzer index = MCV ÷ RBC count. < 13 favours thalassaemia trait; > 13 favours iron deficiency.

Key points

  • Thalassaemia trait: high RBC, low MCV → low index.
  • Iron deficiency: low RBC → high index.
  • Confirm with ferritin and haemoglobin electrophoresis.

References

Worked calculation

The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.

MCV70 fL
RBC count6.0 ×10¹²/L

→Mentzer index11.7

  • Interpretation：< 13 — favours thalassaemia trait
  • Formula：MCV ÷ RBC (RBC in ×10¹²/L)
Verification & sources · governance
FAQ

Frequently asked questions

What are the limits and cautions when using Mentzer Index Calculator?
For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
Does Mentzer Index Calculator upload patient data? Where is it calculated?
Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
How is Mentzer Index Calculator calculated in practice? Can you show a worked example?
Inputs: MCV 70 fL, RBC count 6.0 ×10¹²/L → Result: Mentzer index 11.7（Interpretation: < 13 — favours thalassaemia trait, Formula: MCV ÷ RBC (RBC in ×10¹²/L)）
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