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C3 Complement Factor Unit Converter
Complement Component 3 (C3) is the most abundant and pivotal protein of the complement system, a part of the innate immune system. It serves as the convergence point for all three activation pathways: the classical, alternative, and lectin pathways. Upon activation, C3 is cleaved into C3a (an anaphylatoxin that promotes inflammation) and C3b (an opsonin that tags pathogens for phagocytosis).[Image of acute phase protein response]
C3 is synthesized in the liver and behaves as a positive acute-phase reactant, meaning levels rise during acute inflammation or infection. However, its primary clinical utility is in detecting complement consumption. Low levels of C3 are a hallmark of active systemic lupus erythematosus (SLE), membranoproliferative glomerulonephritis, and other immune-complex diseases where the protein is used up faster than it is produced. This converter allows precise switching between the standard SI unit (g/L) and the conventional mass unit (mg/dL).
SI Units
RecommendedGrams per liter (Standard International).
Conventional Units
*Molar conversion based on C3 MW ≈ 185 kDa.
Clinical Context
Reference Ranges: In healthy adults, serum C3 levels typically range from 90 – 180 mg/dL (0.9 – 1.8 g/L).
Low C3 often indicates active disease in Lupus nephritis or post-streptococcal glomerulonephritis. It is usually evaluated alongside C4; low C3 with normal C4 suggests alternative pathway activation, while low levels of both suggest classical pathway activation. The conversion factor is simple: 1 g/L = 100 mg/dL.
Clinical References
How to Use This Calculator
Follow these steps to get accurate clinical conversions instantly.
Enter Values
Input your laboratory results into the corresponding unit field (e.g., mg/dL). You can use either dot or comma decimals.
Automatic Conversion
The calculator works in real-time. As you type in one field, all other units (like g/L) are instantly updated.
Verify Units
Check the SI Units section. g/L is the standard SI unit, while mg/dL is common in the US.
Reset
Use the Clear button to reset all fields before starting a new calculation.
Frequently Asked Questions & Tips
Typically 90–180 mg/dL. Values below this range suggest complement consumption (active immune disease).
Yes. 1 g/L is exactly equal to 1 mg/mL.