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Alkaline Phosphatase (ALP) Unit Converter
Alkaline Phosphatase (ALP) is a group of isoenzymes that catalyze the hydrolysis of organic phosphate esters in an alkaline environment. While present in many tissues, the highest concentrations are found in the liver (biliary tract epithelium) and bone (osteoblasts). Ideally, specific isoenzyme testing can distinguish the source, but total ALP is the standard screening test.[Image of alkaline phosphatase reaction mechanism]
Clinically, ALP is a primary marker for cholestasis (bile duct obstruction), where levels can rise to 10 times the upper limit of normal. It is also a key indicator of high bone turnover states, such as Paget’s disease, rickets (vitamin D deficiency), and bone metastasis. Because it is an enzyme, results are reported in activity units (U/L or µkat/L). This converter ensures accurate switching between the International Unit (U/L) and the SI katal units used in some European and research settings.
SI Units
RecommendedMicrokatals and Nanokatals per liter.
Conventional Units
Clinical Context
ALP levels are physiologically higher in growing children and pregnant women (placental isoenzyme). In adults, isolated elevation of ALP (with normal ALT/AST) strongly suggests biliary obstruction or bone pathology. To differentiate, Gamma-Glutamyl Transferase (GGT) or 5′-Nucleotidase can be tested; these are elevated in liver disease but normal in bone disease.
Low ALP (Hypophosphatasia) is a rare genetic condition affecting bone mineralization. Reference ranges vary by method but are typically 44 – 147 U/L for adults. The conversion factor is constant: 1 U/L ≈ 0.0167 µkat/L.
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., U/L). 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 µkat/L) are instantly updated.
Verify Units
Check the SI Units section. Both µkat/L and nkat/L are provided as they are standard ISO units for enzymes.
Reset
Use the Clear button to reset all fields before starting a new calculation.
Frequently Asked Questions & Tips
ALP is an enzyme. Clinical labs measure its activity (how much reaction it speeds up), not its physical weight. Therefore, units like U/L are used instead of mg/dL.
Yes, in this context, U/L (Units per Liter) and IU/L (International Units per Liter) are interchangeable.