What this result means
Choose the unit on the blood test, enter the creatinine value, and the converter will express the same concentration in the other unit. It uses the standard factor 88.4, with one-decimal µmol/L and two-decimal mg/dL display rounding. [1][3]
What mg/dL and µmol/L mean
Both units describe creatinine concentration. mg/dL expresses creatinine mass in a decilitre; µmol/L expresses the amount of creatinine substance in a litre. Conversion changes the unit only, not the original sample or result. [2]
Why the factor is 88.4
The National Kidney Foundation uses 88.4 to convert serum creatinine from mg/dL to µmol/L. NIST reports a creatinine molar mass of 113.1182 g/mol; dimensional conversion gives about 88.403 µmol/L per mg/dL, which is represented clinically as 88.4. [1][2]
This factor is specific to creatinine. It must not be reused for glucose, cholesterol, bilirubin or another substance because molecular masses differ. [2]
How the result is rounded
The converter calculates first and rounds once for display. It shows µmol/L to one decimal place and mg/dL to two decimal places to limit avoidable rounding while keeping a readable result. Laboratory reporting precision may differ, so retain the original value and unit. [3]
What the conversion cannot tell you
The converted number does not classify kidney function. Creatinine interpretation can depend on the laboratory method and reference interval, prior results, muscle context and other health information. This page deliberately adds no universal normal, high or low label. [3][4]
A creatinine unit conversion is not an eGFR or creatinine-clearance calculation. Those are separate models with additional inputs, intended populations and limitations. [1][3]
Safe next steps
Keep the original value, unit, laboratory reference interval and test date. Use the converted value only to compare like with like. For interpretation or a decision about care, use the original report and discuss the full context with a qualified health professional.
Formula and assumptions
- Formula
- µmol/L = mg/dL × 88.4. mg/dL = µmol/L ÷ 88.4. The standard factor is consistent with the NIST creatinine molar mass of 113.1182 g/mol after converting decilitres to litres; 88.4 is a rounded clinical factor, not extra measurement precision. [1][2][3]
- Version
- Standard serum creatinine mass-to-amount unit conversion, nkf-nist-creatinine-unit-conversion-v1
- Rounding
- Calculate with 88.4 or its stored reciprocal, then round once for display: one decimal place for µmol/L and two decimal places for mg/dL. These display settings are calculator choices; the source measurement is not changed.
Who this is for — and when not to use it
Intended use
Neutral, reversible unit conversion for a person who already has a serum or plasma creatinine concentration in mg/dL or µmol/L and needs the equivalent display unit.
Not intended for
This tool does not interpret creatinine, calculate eGFR or creatinine clearance, convert urine creatinine or ratios, diagnose kidney disease, set a reference range, or guide medication, treatment or urgent decisions.
Exclusions
- Urine creatinine, 24-hour urine collections or albumin-to-creatinine and protein-to-creatinine ratios
- eGFR, creatinine clearance or medication-dose calculations
- Diagnosis, staging or interpretation of kidney function
- Treatment or urgent-care decisions
- Any analyte other than creatinine
- Changing or correcting the original laboratory measurement
Evidence sources
- 1. Recommendations for Implementing the CKD-EPI 2021 Race-Free eGFR Calculation: Guidelines for Clinical Laboratories — National Kidney Foundation. Accessed Aug 9, 2026.
- 2. Certification of Standard Reference Material 967b: Creatinine in Frozen Human Serum — National Institute of Standards and Technology. Accessed Aug 9, 2026.
- 3. Recommendations for Implementing the CKD-EPI 2021 Race-Free Equations: Practical Guidance for Clinical Laboratories — Clinical Chemistry. Accessed Aug 9, 2026.
- 4. Chronic kidney disease and automatic reporting of estimated glomerular filtration rate: a position statement — Medical Journal of Australia. Accessed Aug 9, 2026.