How do you convert urea (bun) from mg/dL to mmol/L?

Divide by the molar mass. For urea (bun) (28.014 g/mol), 1 mg/dL = 0.356964 mmol/L.

Why isn't there one factor for mg/dL to mmol/L?

Because mg measures mass and mmol measures amount of substance, the factor depends on the molar mass of what is being measured. Every analyte has its own.

Calculators › Urea (BUN)

Urea (BUN): mg/dL to mmol/L

1 mg/dL = 0.356964 mmol/L

Reference only. These conversions are arithmetic, not medical advice. Reference ranges differ between laboratories, and results should be interpreted by a clinician alongside the lab's own reported units and ranges.

Try it — edit the line, the answer updates as you type Open in Jotal

Conversion table

mg/dL	mmol/L
7 mg/dL	2.4988 mmol/L
10 mg/dL	3.5696 mmol/L
14 mg/dL	4.9975 mmol/L
20 mg/dL	7.1393 mmol/L
25 mg/dL	8.9241 mmol/L
30 mg/dL	10.7089 mmol/L
40 mg/dL	14.2786 mmol/L
50 mg/dL	17.8482 mmol/L

Going the other way, 1 mmol/L = 2.8014 mg/dL.

Why this conversion needs the substance

mg/dL measures mass; mmol/L measures amount of substance. Converting between them needs the molar mass of the thing being measured — for urea (bun) that is 28.014 g/mol. That is why a generic converter can't do it, and why every analyte has a different factor.

Jotal works this out from molar mass rather than a stored factor, so write bun 25 mg/dL in mmol/L and it answers 8.9241 mmol/L. Leave the substance out and it deliberately returns nothing rather than guessing.

Other lab values

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