Urine & CSF

Porphobilinogen (24-h urine) unit converter

Porphobilinogen in 24-hour urine (acute porphyria work-up)

Also known as: PBG urine, Urinary porphobilinogen, PBG im Urin

Converter

Enter a value in any unit and all other units fill in.

mg/24 h µmol/24 h

Worked example

9 µmol/24 h (middle of the reference range) = 2.04 mg/24 h

Conversion formulas

mg/24 h	mg/24 h = µmol/24 h × 0.2262	µmol/24 h = mg/24 h × 4.42

Good to know

Porphobilinogen (PBG) in 24-hour urine is reported in mg/24 h or in µmol/24 h. It is raised during attacks of acute porphyria.

mg/24 h × 4.42 = µmol/24 h (exact factor 4.42).
Protect the urine from light; a random urine sample is normally simply reported as negative.

Reference range

Unit	Adults
mg/24 h	0 – 4.072
µmol/24 h	0 – 18

Source: MedlinePlus (NLM): PBG urine test · Last reviewed: 2026-10-19

Note from the source: Below 4 mg/24 h (18 µmol/24 h) (MedlinePlus); a random urine sample is normally negative. Protect the sample from light

Frequently asked questions

How do I convert Porphobilinogen (24-h urine) from µmol/24 h to mg/24 h?

mg/24 h = µmol/24 h × 0.2262. In the other direction: µmol/24 h = mg/24 h × 4.42.

What is the reference range of Porphobilinogen (24-h urine)?

For adults the range is 0 – 18 µmol/24 h (MedlinePlus (NLM): PBG urine test). Reference ranges differ between laboratories and partly by sex and age; use the range printed on your lab report.

Which units are used for Porphobilinogen (24-h urine)?

Common units are mg/24 h, µmol/24 h.