The Serum Iron Saturation (SIS) Calculator determines the percentage of iron bound to transferrin in your blood, a critical marker for evaluating iron metabolism. This tool helps identify iron deficiency anemia, hemochromatosis, and chronic diseases affecting iron utilization.

Formula:
(Equivalent to Transferrin Saturation (TSAT), but focuses on iron’s availability in serum.)
How to Use the Calculator
- Input Values:
- Serum Iron (lab result, in μg/dL).
- TIBC (lab result, in μg/dL).
Calculate SIS:
Example Calculation
- Serum Iron = 80 μg/dL
- TIBC = 350 μg/dL
🧮 Serum Iron Saturation (SIS) Calculator
📐 Formula:
SIS (%) = (Serum Iron / TIBC) × 100
- 🔹 Serum Iron: Iron in the blood (μg/dL)
- 🔹 TIBC: Total Iron Binding Capacity (μg/dL)
Normal Range
Group | SIS (TSAT) Range | Critical Thresholds |
---|---|---|
Adults | 20–50% | <15% (Iron deficiency) >50% (Iron overload) |
Interpretation
SIS Result | Clinical Significance |
---|---|
<15% | Iron deficiency anemia |
15–20% | Early iron deficiency |
20–50% | Normal iron metabolism |
>50% | Hemochromatosis, iron overload, or liver disease |
Key Notes
- Units Must Match: Serum Iron and TIBC must both be in μg/dL.
- Pair with Ferritin:
- Low SIS + Low Ferritin = Iron deficiency.
- Low SIS + High Ferritin = Anemia of chronic disease.
- High SIS + High Ferritin = Hemochromatosis.
- Limitations:
- Affected by inflammation, infections, or liver dysfunction.
- Not diagnostic alone; use with CBC and clinical history.
Quick Reference Table
Condition | SIS | TIBC | Ferritin |
---|---|---|---|
Iron Deficiency | <15% | ↑↑ (High) | ↓↓ (Low) |
Chronic Disease | 15–20% | ↓ (Low) | ↑/Normal |
Hemochromatosis | >50% | ↓ (Low) | ↑↑ (High) |
Calculate SIS to uncover iron disorders and guide treatment decisions!
Based on WHO and ASH guidelines.
Meta Description
“Calculate Serum Iron Saturation (SIS) to diagnose iron deficiency or overload. Learn the formula, normal ranges, and how to interpret results with ferritin and TIBC.”
Description
The Serum Iron Saturation (SIS) Calculator measures the percentage of iron bound to transferrin in your blood, critical for diagnosing iron deficiency anemia, hemochromatosis, and chronic diseases.
- Formula:
- Example: Serum Iron = 50 μg/dL, TIBC = 400 μg/dL → SIS = 12.5% (Iron deficiency).
- Key Features:
- Identifies iron deficiency (SIS <15%) or overload (SIS >50%).
- Works with TIBC and ferritin for comprehensive iron studies.
- Clinical Use:
- Guides treatment for anemia, chronic kidney disease, or hereditary hemochromatosis.
- Essential for clinicians, students, and patients managing iron-related conditions.
Normal Ranges:
- SIS (TSAT): 20–50%
- Serum Iron: 60–170 μg/dL (men), 50–150 μg/dL (women)
- TIBC: 240–450 μg/dL
Free and accurate – analyze iron status in seconds!
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The content on LabTestsGuide.com is for informational and educational purposes only. We do not guarantee the accuracy, completeness, or timeliness of the information provided. Always consult qualified healthcare professionals for medical advice, diagnosis, or treatment. LabTestsGuide.com is not liable for any decisions made based on the information on this site.