Online Medical Tools — Lab Unit Converter
Printed on 8/14/2026
For informational purposes only. This is not medical advice.
Lab Unit Converter
Laboratory values are reported in different units depending on the country: conventional units are standard in the US, while SI (Système International) units are used in most other countries and in scientific literature. This converter handles 20 commonly tested lab values, allowing quick conversion between the two systems. After converting creatinine values, calculate eGFR Calculator or Creatinine Clearance for kidney function. For calcium conversions, use in Corrected Calcium Calculator. For bilirubin and albumin, apply results to Child-Pugh Score or MELD Score.
Formula: SI value = Conventional value × Conversion factor
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How It Works
Select the lab test from the dropdown
Choose the specific laboratory analyte from the list of 20+ common tests including glucose, creatinine, cholesterol, bilirubin, hemoglobin, electrolytes, uric acid, and others. Each analyte has its own unique conversion factor derived from its molecular weight.
Enter the value and select conversion direction
Input the numeric lab value and select whether you are converting from Conventional (US) units to SI units, or from SI units back to Conventional. Common conventional units include mg/dL, g/dL, and mEq/L. Common SI units include mmol/L, µmol/L, and g/L.
Read the converted value for the target unit system
The converted value is displayed instantly using the analyte-specific conversion factor. Always compare the converted result to reference ranges appropriate for the target unit system — reference ranges are unit-specific and cannot be applied across systems without adjustment.
Who Uses the Lab Unit Converter
Interpreting International Medical Literature
Physicians, researchers, medical students
Most European, Asian, Canadian, and Australian journals report laboratory values in SI units, while US clinical practice uses conventional units. Convert values encountered in research papers, clinical guidelines (e.g., ESC cardiovascular guidelines using mmol/L for cholesterol), or international case reports to your familiar unit system for accurate clinical interpretation.
Telemedicine Across Countries
Telemedicine physicians, international consultants
When consulting on patients across national borders, lab results frequently arrive in unfamiliar units. A creatinine of 300 µmol/L (SI) versus 3.4 mg/dL (conventional) represents the same value but may be misinterpreted without conversion. Accurate conversion is essential for appropriate dosing and renal function assessment.
Medical Education and Board Exam Preparation
Medical students, residents, educators
Board examinations (USMLE, MCCQE, PLAB) may present values in either unit system. Familiarity with key conversions — glucose mg/dL to mmol/L, creatinine mg/dL to µmol/L, cholesterol mg/dL to mmol/L — is essential for answering clinical vignettes correctly and for reading international literature during training.
Pharmacy and Drug Dosing Calculations
Pharmacists, clinical pharmacologists
Drug dosing thresholds are often specified in one unit system in the original study or guideline. Dosing of aminoglycosides based on creatinine clearance, statin initiation based on LDL cholesterol thresholds, and metformin contraindication based on creatinine/eGFR all require correct unit interpretation. This tool ensures dosing calculations use the correct numeric value.
Clinical Research and Database Entry
Clinical researchers, data managers
Research databases and multi-site trials often standardize on one unit system (usually SI). Converting patient lab values from local conventional units to SI for data entry prevents systematic data errors. Similarly, exporting research data for US clinical use may require SI-to-conventional conversion across thousands of records.
Pro Tips
Critical conversions every clinician should know
Key conversions: Glucose: 1 mg/dL = 0.0555 mmol/L (or divide by 18). Creatinine: 1 mg/dL = 88.4 µmol/L. Total cholesterol: 1 mg/dL = 0.0259 mmol/L (or divide by 38.7). Bilirubin: 1 mg/dL = 17.1 µmol/L. Hemoglobin: 1 g/dL = 10 g/L. Albumin: 1 g/dL = 10 g/L. Uric acid: 1 mg/dL = 59.5 µmol/L.
US is nearly alone in using conventional units
The United States remains one of the only countries that routinely uses conventional units (mg/dL) for glucose, cholesterol, and creatinine. The UK, EU, Australia, and most of Asia use SI units. Clinicians reading any international guideline — ESC for cardiology, WHO for diabetes, KDIGO for nephrology — will encounter SI values.
Clinical cutoffs change by unit system
The diagnostic threshold for diabetes on fasting glucose is 126 mg/dL in conventional units and 7.0 mmol/L in SI — these represent the same value, but must be matched to the correct reference range. LDL target of 70 mg/dL (US) equals 1.8 mmol/L (EU). Always use the reference range for the unit system you are working in.
Sodium and potassium: mEq/L equals mmol/L for monovalent ions
For monovalent ions (Na+, K+, Cl-, HCO3-), mEq/L equals mmol/L exactly — a 1:1 conversion. Serum sodium of 140 mEq/L = 140 mmol/L. These are not different values; they are the same measurement expressed in equivalent units. No numeric conversion is required.
Calcium requires care: mEq/L vs mmol/L for divalent ions
For divalent ions like calcium (Ca2+), 1 mmol/L = 2 mEq/L because each calcium ion contributes 2 equivalents. Normal serum calcium is 8.5-10.5 mg/dL = 2.1-2.6 mmol/L = 4.3-5.2 mEq/L. Using the wrong conversion for calcium can produce seemingly abnormal values.
eGFR and INR require no conversion
Estimated GFR (eGFR) is reported universally as mL/min/1.73m2 in all countries — no conversion needed. INR is a dimensionless ratio — no conversion. HbA1c may be reported as % (NGSP) or mmol/mol (IFCC); these require separate conversion: NGSP% = (IFCC mmol/mol / 10.929) + 2.15.
Troponin units vary by assay — check your lab's reference range
Cardiac troponin is measured in ng/mL, pg/mL, or ng/L depending on the assay (conventional vs high-sensitivity). There is no universal conversion — each assay has its own reference range and 99th percentile cutoff. Never apply one troponin assay's threshold to another without confirming the assay type.
Glucose unit confusion causes real patient harm
Glucose unit confusion is a documented source of dangerous medication errors. A diabetic patient reporting glucose of 12 may mean 12 mmol/L (normal-high, ~216 mg/dL) or 12 mg/dL (severe hypoglycemia) depending on their country's convention. Always confirm the unit system when interpreting patient-reported glucose values from different countries.
Phosphorus and magnesium conversions
Phosphorus: 1 mg/dL = 0.323 mmol/L. Normal range 2.5-4.5 mg/dL = 0.81-1.45 mmol/L. Magnesium: 1 mg/dL = 0.411 mmol/L = 0.822 mEq/L. Normal magnesium is 1.7-2.2 mg/dL = 0.70-0.90 mmol/L. These conversions matter in refeeding syndrome, renal failure, and electrolyte management.
Common Questions About Your Results
Evidence-Based Methodology
SI unit adoption by WHO/IUPAC: IUPAC-IFCC Recommendations (Clin Chem 1987). Conversion factors derived from molecular weights per NIST standard atomic weights. US conventional unit persistence: documented in JAMA (Young 1987). HbA1c conversion (NGSP/IFCC): IFCC Working Group on HbA1c standardization. Glucose unit confusion as medication error risk: ISMP Safety Alert (2007). Complete conversion reference: Harrison's Principles of Internal Medicine (21st ed.) Appendix; NIH MedlinePlus laboratory reference tables.
Clinical Content Trust
- Last reviewed:
- April 21, 2026
- Guideline version:
- General evidence framework v2026.04
- Source set version:
- Primary-source set v1
How to Interpret Your Result
Your converted value represents the same laboratory measurement expressed in the alternative unit system. The conversion is based on the molecular weight of the analyte and standard conversion factors used in clinical chemistry. Conventional units (used primarily in the US) and SI units (used internationally and in scientific literature) measure the same quantity but express it differently.
When interpreting your converted result, always compare it to the appropriate reference range for the unit system you are converting to. Reference ranges are unit-specific, and a value that appears normal in one system may look alarming if mistakenly compared to a reference range in the other system. For example, a glucose of 100 mg/dL is normal, but the equivalent 5.6 mmol/L should be compared against SI reference ranges, not conventional ones.
When to Use This Tool
Use this converter when reading medical literature, research papers, or clinical guidelines that report laboratory values in a different unit system than what your local laboratory uses. It is particularly important when consulting international guidelines or studies, as most non-US publications use SI units while US laboratories report in conventional units.
It is also useful when caring for patients who have laboratory results from another country, when communicating with international colleagues, or when entering data into research databases that require a specific unit format. Pharmacists and researchers frequently need these conversions for drug dosing studies and pharmacokinetic calculations.
Limitations
While most conversion factors are precise and based on well-established molecular weights, some analytes have approximate conversion factors due to variable molecular composition. Proteins such as albumin and immunoglobulins have conversions based on average molecular weights that may not be exact for every clinical scenario.
This tool converts between the two most common unit systems but does not cover all possible units for every analyte. Some specialized tests may use unique units not included here. Additionally, the tool does not adjust reference ranges during conversion. You must look up the appropriate reference range for the target unit system independently.
Unit conversion errors are a recognized source of medical errors, particularly for glucose and creatinine. Always double-check converted values against known clinical ranges and verify the conversion direction before making clinical decisions based on converted results.
Disclaimer: This tool is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about your health.
Changelog
April 21, 2026 · trust-baseline
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