Lab Unit Converter

Conversion of 33 lab analytes between SI (mmol/L, µmol/L, nmol/L, pmol/L) and conventional units (mg/dL, ng/mL, pg/mL) by molar mass.

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Result

In SI units: 5.20 mmol/L
In conventional units: 94 mg/dL
Conversion factor: 0.0555 mmol/L / mg/dL

AMA and Labcorp laboratory factors. Check units and assay calibration on the report. Reference ranges are population benchmarks from the cited sources. Laboratories use their own ranges, and interpretation depends on clinical context: discuss the result with your physician.

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How it is calculated

A factor converts mass concentration into molar concentration using molar mass and volume units. The tool uses common laboratory factors from AMA and Labcorp. Insulin and prolactin factors depend on assay calibration: you can enter your laboratory’s factor. For urea, mg/dL refers to BUN, the mass of urea nitrogen, not the mass of the whole urea molecule.

Formula

SI = conventional value × factor. Reverse conversion: SI ÷ factor. Check your laboratory’s factor for insulin and prolactin; mg/dL BUN and mg/dL urea are not interchangeable.

Limits of the method

Unit conversion does not interpret results or diagnose. Reference intervals depend on the laboratory and method; convert their limits separately. Verify insulin and prolactin factors with the laboratory. BUN conversion is not suitable for a result labelled urea in mg/dL.

Sources of the method

This calculation is for reference only and is not medical advice, a diagnosis or a prescription. If you have a medical condition, are pregnant, take medication or have any doubts, discuss the result with a physician or a qualified nutrition professional.

How to convert lab units

Choose the analyte

The list has the 33 most common analytes — from glucose and cholesterol to vitamin D, testosterone and cortisol. Cholesterol, LDL and HDL share one factor.

Set the direction

SI → conventional if your report is in mmol/L or nmol/L and the reference from a foreign paper is in mg/dL or ng/mL. And vice versa if the test was done abroad.

Convert the reference range, not just the number

Reference intervals depend on the lab method. Convert the normal limits from your report too, so you compare the value against the right range.

Unit conversion examples

Glucose5.6 mmol/L = 101 mg/dL

A European lab report and a US paper

5.6 ÷ 0.0555 ≈ 101 mg/dL. This is an arithmetic unit conversion, not a diagnosis.

Unit conversion does not make different clinical guidelines equivalent.

Vitamin D30 ng/mL = 75 nmol/L

One concentration in different units

30 × 2.496 = 74.88 nmol/L. These numbers describe the same concentration; they do not establish a universal target or vitamin D dose.

Endocrine Society 2024 does not establish a universal 25(OH)D target for disease prevention in healthy people.

Testosterone12 nmol/L = 346 ng/dL

Testosterone: converting units

12 ÷ 0.0347 ≈ 346 ng/dL. Interpretation depends on the assay, symptoms and clinical guidance.

Free testosterone has its own calculator.

Why the world has two unit systems

mg/dL expresses mass per unit volume, while mmol/L expresses amount of substance. The factor depends on the analyte’s molar mass; the glucose factor cannot be used for cholesterol or triglycerides.

Where people most often get it wrong

Ferritin: ng/mL = µg/L. Hemoglobin: g/dL × 10 = g/L. Creatinine: mg/dL × 88.4 = µmol/L. BUN and urea in mg/dL are different quantities. Hormones reported in biological activity units require the assay-specific factor.

Factor table for common analytes

Analyte	SI ↔ conventional units	Conversion
Glucose	mmol/L ↔ mg/dL	mg/dL × 0.0555 = mmol/L
Cholesterol (TC, LDL, HDL)	mmol/L ↔ mg/dL	mg/dL × 0.02586 = mmol/L
Triglycerides	mmol/L ↔ mg/dL	mg/dL × 0.01129 = mmol/L
Creatinine	µmol/L ↔ mg/dL	mg/dL × 88.4 = µmol/L
Uric acid	µmol/L ↔ mg/dL	mg/dL × 59.48 = µmol/L
Bilirubin	µmol/L ↔ mg/dL	mg/dL × 17.1 = µmol/L
Vitamin D, 25(OH)D	nmol/L ↔ ng/mL	ng/mL × 2.496 = nmol/L
Insulin	pmol/L ↔ µIU/mL	µIU/mL × 6.945 = pmol/L
Vitamin B12	pmol/L ↔ pg/mL	pg/mL × 0.738 = pmol/L
Testosterone	nmol/L ↔ ng/dL	ng/dL × 0.0347 = nmol/L
Cortisol	nmol/L ↔ µg/dL	µg/dL × 27.59 = nmol/L
Hemoglobin, albumin	g/L ↔ g/dL	g/dL × 10 = g/L

Factors are rounded. For insulin and prolactin, use your laboratory’s factor if it differs from the table.

Frequently asked questions

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

Divide mg/dL by 18.016 (or multiply by 0.0555). For example, 100 mg/dL = 5.55 mmol/L, 126 mg/dL = 7.0 mmol/L. To go back, multiply mmol/L by 18.016.

What is the difference between ng/mL and nmol/L for vitamin D?

For 25(OH)D, 1 ng/mL = 2.496 nmol/L. For example, 20 ng/mL ≈ 50 nmol/L. Conversion does not determine a diagnosis, target or need for supplements.

Why does ferritin not change on conversion?

Ferritin is measured in µg/L and ng/mL, and these are identical: 1 µg/L = 1 ng/mL. Molar units are not used for ferritin because it is a large protein of variable mass.

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

Multiply mg/dL by 88.4: 1.0 mg/dL = 88.4 µmol/L. Kidney function equations must receive the units specified by the equation.

Are the factors accurate for hormones?

Factors are stable for substances with a defined molar mass. For insulin and prolactin, activity depends on the assay calibrator: verify your laboratory’s factor and change it in the form if needed.

After converting units you can calculate clinical indices right away:

HOMA-IR Calculator: Insulin Resistance Index →Lipid Panel Calculator: LDL, non-HDL and Atherogenic Indices →eGFR Calculator (CKD-EPI 2021) →Vitamin D: van Groningen model estimate →HbA1c ↔ Average Glucose (eAG) Converter →

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What next

Formula breakdowns, biomarker reference ranges and nutrition articles with cited sources are in the NutriFit knowledge base.

Go to the knowledge base