Urea nitrogen (BUN)
Blood urea nitrogen (BUN) is the same thing as urea, on a different scale: the one used in the US.
At a glance
- Sample
- Blood
- Units
- mg/dL (US), mmol/L (Europe)
- Often looked at with
- Creatinine, eGFR, Urea, Uric acid
- Preparation
- No special preparation is usually needed. If other tests are done from the same sample, you may be asked to come fasting.
Units: mg/dL and mmol/L
US labs print urea nitrogen (BUN) in mg/dL; European labs print urea itself in mmol/L, which is the same number of molecules. To convert, divide mg/dL by 2.8014.
mmol/L = mg/dL ÷ 2.8014 · molar mass 28.014 g/mol
This converter changes units only. It doesn’t tell you whether a number is in or out of any range: that depends on the range printed by your own lab, and on your doctor. Soma does not diagnose and is not medical advice.
Urea nitrogen (BUN) mg/dL to mmol/L: converter and every value
Why lab ranges differ
Each lab sets its reference range for its own method and analyser, and many ranges differ by age and sex. Two labs can print different ranges for the same blood, so a result is read against the range on its own report, not against a number from another lab or a website.
Soma charts every urea nitrogen (BUN) result against the range printed by the lab that measured it.
What can affect the result
- Protein-rich food the day before.
- Dehydration before the test.
- Intense exercise.
If something like this applies, mention it to the doctor who reads your results.
Questions
How do I convert urea nitrogen (BUN) from mg/dL to mmol/L?
Divide mg/dL by 2.8014. For example, 15 mg/dL is 5.35 mmol/L.
Why does my lab’s urea nitrogen (BUN) range differ from another lab’s?
Each lab sets its range for its own method and equipment, and many ranges differ by age and sex. That’s why a result is best read against the range printed on the same report.
How do I prepare for a urea nitrogen (BUN) test?
No special preparation is usually needed. If other tests are done from the same sample, you may be asked to come fasting. Follow your lab’s instructions.
Related tests
Got a lab report with Urea nitrogen (BUN)?
Share it to Soma: it reads every row on your phone, with no account and no upload, and puts your urea nitrogen (BUN) on one chart with your earlier results, each against the range your lab printed.
Sources
- BUN (Blood Urea Nitrogen) — MedlinePlus, U.S. National Library of Medicine.
- Units: PubChem: Nitrogen (the two nitrogen atoms of urea, N₂), molar mass 28.014 g/mol, as the Soma app converts.
Mention of a source doesn’t mean it endorses Soma. This page explains the test; it doesn’t diagnose and is not medical advice. Talk to your doctor about what your results mean.