Urine Creatinine Unit Converter

Convert urine creatinine between mg/dL, mmol/L, g/L and µmol/L — the denominator that makes a spot albumin or protein ratio usable without a timed collection.

Last updated 3 Sep 2026

Urine Creatinine converter

Mass ⇄ molar

Urine creatinine

Divide mmol/L by 0.0884 to return to mg/dL.

Reference groupA random adult urine creatinine usually falls between 20 and 300 mg/dL. The width of that range is the point: it reflects hydration, not kidney function.

10.61mmol/LExample

Urine creatinine 120 mg/dL

Formula and conversion factor

mmol/L = mg/dL × 0.0884
µmol/L = mg/dL × 88.40
g/L = mg/dL ÷ 100

0.0884: derived from the molecular weight of creatinine, 113.12 Da — the same factor used for serum creatinine
concentration: urine creatinine runs one to two orders of magnitude above serum creatinine, typically 20–300 mg/dL against 0.6–1.2 mg/dL
role: used almost entirely as a denominator, to correct a spot urine for how dilute or concentrated it happens to be

Worked example

Urine creatinine 120 mg/dL
120 × 0.0884 = 10.61 mmol/L
120 × 88.40 = 10,608 µmol/L
120 ÷ 100 = 1.200 g/L

Urine and serum creatinine compared

The same conversion factor applies to urine and serum creatinine; only the scale of the numbers differs.
	mg/dL	mmol/L	µmol/L
Serum, adult reference interval	0.6 – 1.2	0.05 – 0.11	53 – 106
Random urine, usual range	20 – 300	1.77 – 26.52	1,768 – 26,521
Dilute urine — ratios unreliable	< 20	< 1.77	< 1,768
Concentrated urine	> 300	> 26.52	> 26,521

Why urine creatinine is measured at all

Urine creatinine is measured on the same analyser, and converted with the same factor, as serum creatinine: 1 mg/dL is 0.0884 mmol/L, or 88.4 µmol/L. What differs is scale. A random adult urine usually contains 20 to 300 mg/dL against roughly 0.6 to 1.2 mg/dL in serum, one to two orders of magnitude higher. That gap is a frequent source of confusion, because a urine result read as though it were a serum value looks catastrophic, and a serum value entered into a urine field looks like an almost water-clear specimen.

Almost all of the value of a urine creatinine lies in its use as a denominator. Creatinine is excreted at a roughly constant rate through the day, so dividing another urinary analyte by it removes the effect of how dilute or concentrated that particular sample happened to be. This is what makes the albumin-to-creatinine and protein-to-creatinine ratios usable on a spot sample, and it is why timed 24-hour collections are no longer needed for routine quantification of proteinuria.

The assumption behind that normalisation is the weak point. Creatinine excretion tracks muscle mass, so a frail, elderly or cachectic patient excretes less creatinine than the ratio assumes and their spot protein-to-creatinine ratio overestimates true protein excretion. A large, muscular patient excretes more, and the same ratio under-corrects and understates it. The bias is systematic rather than random, so repeating the sample does not remove it.

The extremes of concentration matter too. A very dilute urine, below about 20 mg/dL of creatinine, makes any ratio derived from it unreliable, because the denominator is small and its measurement error is proportionally large. A very concentrated sample carries the mirror problem. Where a ratio is going to be acted on, take it from a first or early morning sample rather than one produced after a large fluid load, and repeat anything that sits awkwardly with the clinical picture.

Frequently asked questions

How do I convert urine creatinine from mg/dL to mmol/L?

Multiply by 0.0884, derived from the molecular weight of creatinine, 113.12 Da. A urine creatinine of 120 mg/dL is 10.61 mmol/L.

Is the conversion factor different for urine and serum creatinine?

No — the molecule is the same, so the factor is identical. Only the concentrations differ, with urine typically one to two orders of magnitude higher than serum.

Why is urine creatinine used as a denominator?

Because creatinine is excreted at a roughly constant rate, dividing by it corrects a spot sample for how dilute it is. That is what allows albumin-to-creatinine and protein-to-creatinine ratios to be interpreted without a timed collection.

When is a spot ratio unreliable?

In people with low muscle mass, where the ratio overestimates protein excretion, and in the very muscular, where it underestimates it. A very dilute urine, below about 20 mg/dL of creatinine, also makes any derived ratio unreliable.

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References

KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S).
Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector’s The Kidney. 11th ed. Elsevier; 2020.