Enter patient details
Example data table
| Case | Age | Sex | Pregnant | Hb (g/dL) | Altitude (m) | Expected severity |
|---|---|---|---|---|---|---|
| A | 32 years | Female | No | 11.2 | 0 | Mild anemia |
| B | 40 years | Male | N/A | 9.5 | 300 | Moderate anemia |
| C | 28 years | Female | Yes | 10.3 | 1200 | Mild anemia (after adjustment may differ) |
| D | 8 years | Male | N/A | 10.9 | 0 | Moderate anemia |
| E | 2 years | Female | N/A | 6.8 | 0 | Severe anemia |
Example severities follow common WHO-style cutoffs. Clinical practice may vary by lab, region, and comorbidities.
Formula used
- Unit conversion: Hb is converted to g/dL (g/L ÷ 10; mmol/L ÷ 0.6206).
- Altitude adjustment (optional): an adjustment value (g/dL) is subtracted from measured Hb before grading.
- Severity grading: the adjusted Hb is compared to group cutoffs (age/sex/pregnancy) to label normal, mild, moderate, or severe.
- Estimated deficit: max(0, cutoff − adjusted Hb) summarizes how far below the lower limit the value is.
How to use this calculator
- Enter age, sex, pregnancy status, and hemoglobin value with units.
- Add altitude if testing occurred at higher elevations.
- Optionally enter MCV and ferritin for context hints.
- Press Calculate Severity to view results above the form.
- Use Download CSV or Download PDF to save a report.
If results are severe or symptoms are significant, seek medical advice promptly.
Hemoglobin thresholds used for grading
Severity is determined by comparing adjusted hemoglobin to group cutoffs. Adults use 13.0 g/dL (men) and 12.0 g/dL (non‑pregnant women) as the lower normal limits. Pregnancy and children 6–59 months use 11.0 g/dL. Children 5–11 years use 11.5 g/dL, and ages 12–14 years use 12.0 g/dL. Mild anemia is typically 11.0–(cutoff−0.1) g/dL for most groups, while moderate anemia spans 8.0–10.9 g/dL, and severe anemia is <8.0 g/dL. For pregnancy and 6–59 months, mild is 10.0–10.9, moderate is 7.0–9.9, and severe is <7.0 g/dL.
Unit conversion and reporting consistency
Laboratories may report hemoglobin in g/dL, g/L, or mmol/L. This calculator converts values to g/dL so one grading rule can be applied. The conversion used is g/L ÷ 10 = g/dL. For mmol/L (hemoglobin), g/dL = mmol/L ÷ 0.6206. Converting first avoids misclassification caused by unit mix‑ups, especially when copying results from lab portals or paper reports.
Altitude adjustment and why it matters
Higher altitude increases hemoglobin through physiologic adaptation. If you enable altitude adjustment, the tool subtracts an adjustment factor from measured hemoglobin before grading. The adjustment rises with elevation (for example, about 0.2 g/dL at 1000 m, 0.8 at 2000 m, 1.9 at 3000 m, and 3.5 at 4000 m), using linear interpolation between breakpoints. This produces a sea‑level equivalent estimate that better aligns with standard cutoffs.
Context markers to support clinical reasoning
MCV and ferritin do not change the severity grade, but they help frame next steps. An MCV <80 fL suggests microcytosis, commonly seen with iron deficiency or thalassemia traits. An MCV 80–100 fL is normocytic, often linked to blood loss or chronic disease. An MCV >100 fL suggests macrocytosis and can reflect B12 or folate issues. Ferritin values <30 ng/mL may indicate depleted iron stores, while higher values can rise with inflammation and should be interpreted alongside clinical context.
Result interpretation, limitations, and safe actions
The output summarizes group, adjusted hemoglobin, severity band, and an estimated hemoglobin deficit versus the normal cutoff. Tracking repeat measurements is useful: a 1.0 g/dL rise after therapy often indicates response, while falling values over weeks suggest ongoing loss, hemolysis, or under‑replacement and needs review. Because anemia is a finding, not a diagnosis, the same severity level can arise from very different causes. Recent bleeding, pregnancy, kidney disease, infection, or nutritional deficiency can shift urgency. If the calculator indicates severe anemia, or if symptoms such as chest pain, fainting, marked shortness of breath, or heavy bleeding are present, seek urgent clinical evaluation. Use the CSV or PDF export to share consistent values during follow‑up.
FAQs
What hemoglobin unit should I enter?
Enter the unit shown on your lab report: g/dL, g/L, or mmol/L. The calculator converts everything to g/dL before grading to prevent unit‑mix errors.
Why does altitude adjustment change the result?
At higher elevations, hemoglobin rises naturally. The tool subtracts an altitude factor to estimate a sea‑level equivalent, helping standard cutoffs remain comparable across locations.
Do MCV and ferritin change the severity grade?
No. Severity is based on hemoglobin and patient group only. MCV and ferritin provide optional context hints that may support discussions about likely causes and next investigations.
Is this a diagnosis of anemia cause?
No. It grades the severity of a hemoglobin result and highlights safety notes. Diagnosing the cause requires history, examination, and additional tests such as iron studies, B12/folate, kidney function, or bleeding assessment.
When should I seek urgent care?
Seek urgent help if the result is severe, symptoms are significant, or there is heavy bleeding. Chest pain, fainting, severe shortness of breath, or rapidly worsening weakness should be treated as emergencies.
Can I use it for infants under 6 months?
Not reliably. This calculator uses reference ranges that start at 6 months. For younger infants, hemoglobin varies by age and prematurity, so use pediatric clinical guidance and local lab reference intervals.