Bilirubin Fraction Calculator
Calculate Indirect Bilirubin and assess liver panel ratios.
Understanding Your Bilirubin (TB) Results
Total Bilirubin (TB) is a measurement of the yellowish pigment that is made during the normal breakdown of red blood cells. Bilirubin passes through the liver and is eventually excreted out of the body. Measuring these levels is a critical part of a Liver Function Test (LFT).
This calculator helps you determine the amount of Indirect Bilirubin, which is the difference between the Total and the Direct (conjugated) levels. Understanding these individual components helps clinicians identify whether a health issue stems from liver damage, bile duct blockage, or increased red blood cell destruction.
The TB Calculation Formula
The math behind the bilirubin fraction is straightforward but essential for medical diagnostics:
Indirect Bilirubin = Total Bilirubin – Direct Bilirubin
Normal Ranges for Adults
- Total Bilirubin: 0.1 to 1.2 mg/dL
- Direct Bilirubin: 0.0 to 0.3 mg/dL
- Indirect Bilirubin: 0.2 to 0.8 mg/dL
Example Calculation
If a laboratory report shows a Total Bilirubin of 2.5 mg/dL and a Direct Bilirubin of 0.5 mg/dL:
- Total (2.5) – Direct (0.5) = 2.0 mg/dL
- The Indirect Bilirubin is 2.0 mg/dL.
- Result: This indicates "Unconjugated Hyperbilirubinemia," which might suggest issues like hemolysis or Gilbert's Syndrome.
Why Monitor Total Bilirubin?
Elevated TB levels often lead to jaundice—a yellowing of the skin and eyes. High levels are commonly associated with:
- Liver Cirrhosis: Long-term scarring of the liver.
- Hepatitis: Inflammation of the liver.
- Gallstones: Blockage of the bile ducts.
- Hemolytic Anemia: When red blood cells are destroyed faster than they can be replaced.
Disclaimer: This calculator is for educational purposes only. Always consult a healthcare professional to interpret lab results.