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Ammonia (NH3) Unit Converter
Ammonia (NH3) is a waste product of protein catabolism and bacterial metabolism in the gut. Under normal physiological conditions, ammonia is transported to the liver via the portal vein, where it is converted into urea through the Urea Cycle and subsequently excreted by the kidneys.[Image of urea cycle]
Elevated plasma ammonia (hyperammonemia) is a medical emergency because ammonia is highly neurotoxic. It can cross the blood-brain barrier, causing astrocyte swelling and hepatic encephalopathy. Causes include severe liver failure (cirrhosis, acute failure), portosystemic shunts, and inborn errors of metabolism (Urea Cycle Disorders). Accurate measurement requires strict pre-analytical control (samples must be placed on ice and analyzed immediately to prevent false elevations from in-vitro deamination). This converter switches between the SI unit (µmol/L) and conventional mass units like µg/dL.
SI Units
RecommendedMicromoles per liter (Standard International).
Conventional Units
Clinical Context
Ammonia reference ranges vary by age. Newborns have higher physiological levels (up to 150 µmol/L) due to immature liver function. In adults, normal venous ammonia is typically 11 – 32 µmol/L (19 – 54 µg/dL).
Arterial samples are preferred for assessing hepatic encephalopathy but are difficult to obtain. Venous samples drawn without a tourniquet (to prevent hemolysis and muscle ammonia release) are the standard. The conversion factor is based on the molecular weight of NH3 (17.03 g/mol): 1 µmol/L ≈ 1.703 µg/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., µmol/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 µg/dL) are instantly updated.
Verify Units
Check the SI Units section. µmol/L is the worldwide standard for ammonia.
Reset
Use the Clear button to reset all fields before starting a new calculation.
Frequently Asked Questions & Tips
Blood cells continue to produce ammonia after collection. Cooling the sample slows this metabolism to prevent falsely high results.
Currently, all fields are editable. If a field seems locked, try clearing the form first.