Clinical Concentration Converter

Convert between mg/dL and mmol/L for glucose, cholesterol, and other lab values — bridging conventional and SI medical units.

Clinical Concentration

mg/dL, mmol/L (glucose)

From

Result

0.055499

1 mg/dL = 0.05549944 mmol/L (glucose)

Popular conversions

What Is a Clinical Concentration Converter?

A clinical concentration converter translates the concentration of a substance in blood between the two systems used in medicine — milligrams per decilitre (mg/dL), common in the US, and millimoles per litre (mmol/L), the SI standard used in much of the world. Lab values for glucose, cholesterol, and many other analytes are reported in one system or the other, so converting is essential to interpret results across borders and references.

The key point is that this conversion is substance-specific: it depends on the molecule's molar mass, so glucose, cholesterol, and creatinine each have their own factor. This converter applies the appropriate molar-mass relationship for common analytes. It is an educational and reference aid — clinical interpretation of any lab value should always involve a qualified healthcare professional.

This is one category of the full Unit Converter — pair it with our percentage calculator or scientific calculator for related everyday maths.

How Clinical Concentration Conversion Works

mg/dL ↔ mmol/L via molar mass

Converting between mass (mg/dL) and molar (mmol/L) concentration requires the substance's molar mass, so each analyte has its own factor.

Glucose: factor of 18.0182

For glucose, mg/dL ÷ 18.0182 = mmol/L. So 90 mg/dL is about 5.0 mmol/L — a normal fasting level.

Cholesterol: factor of 38.67

For cholesterol, mg/dL ÷ 38.67 = mmol/L. A 200 mg/dL total cholesterol is about 5.17 mmol/L.

Substance-specific, not universal

Because the factor depends on molar mass, you can't use one number for all analytes — using glucose's factor for cholesterol is wrong.

Core Clinical Concentration Factors

Each analyte has its own factor, set by its molar mass. These are the most common.

Glucose mg/dL → mmol/L

÷ 18.0182

Glucose's molar mass gives this factor. 90 mg/dL ≈ 5.0 mmol/L.

Cholesterol mg/dL → mmol/L

÷ 38.67

Total and LDL/HDL cholesterol use this factor. 200 mg/dL ≈ 5.17 mmol/L.

General relationship

mmol/L = (mg/dL × 10) / M

Where M is the molar mass — the basis for every analyte's specific factor.

How to Use the Concentration Converter

1
Identify the analyte
The factor depends on the substance (glucose, cholesterol, etc.), so know which lab value you're converting.
2
Enter the value
Type the concentration you want to convert — a glucose or cholesterol reading, for example.
3
Choose 'from' and 'to' units
Select mg/dL or mmol/L, then swap to reverse direction.
4
Interpret with a professional
Use the converted value to compare against a reference range — but discuss clinical meaning with a healthcare provider.

Key Clinical Concentration Concepts

mg/dL (conventional units)

Mass per decilitre, used in the US and a few other countries. Reports the mass of a substance in a tenth of a litre of blood.

mmol/L (SI units)

Millimoles per litre, the SI standard used in most of the world. Reports the number of molecules (in moles) per litre.

Molar mass dependence

Converting mass to moles needs molar mass, so each analyte has a unique factor. Glucose ≈ 18.02; cholesterol ≈ 38.67.

Reference ranges differ by unit

A normal fasting glucose is ~70–100 mg/dL or ~3.9–5.6 mmol/L. The range, like the value, depends on the unit system.

Real-World Concentration Conversions

🩸

Blood glucose

A fasting glucose of 90 mg/dL is 5.0 mmol/L. Diabetics tracking levels across US and SI references convert constantly.

❤️

Cholesterol

A total cholesterol of 200 mg/dL is 5.17 mmol/L. Lipid panels report in either system by country.

🌍

International results

A US lab reports glucose in mg/dL; a European one in mmol/L. Travellers and clinicians convert to compare.

📱

Glucose monitors

Continuous glucose monitors can display either unit. Converting helps interpret a reading set to the unfamiliar system.

🔬

Diabetes thresholds

A diabetes diagnosis threshold of 126 mg/dL fasting is 7.0 mmol/L. The cutoff converts between the two systems.

📊

Lab comparison

Comparing an old mg/dL result to a new mmol/L one requires conversion to track a trend accurately.

Best Practices for Clinical Concentration Conversion

✓Use the right factor per analyte. The conversion depends on molar mass, so glucose (18.02), cholesterol (38.67), and others each have their own factor. Never reuse one for another.
✓Match reference ranges to the unit. A value is only meaningful against a range in the same units. Convert both the value and the reference range consistently.
✓Mind which substance a panel reports. Lipid panels, glucose, and creatinine all use different factors. Confirm the analyte before applying a conversion.
✓Treat it as a reference aid. Unit conversion supports interpretation but doesn't replace clinical judgement. Discuss results with a healthcare professional.
✓Keep sensible precision. Lab values carry limited precision. Reporting glucose to many decimal places implies accuracy the measurement doesn't have.

Common Clinical Concentration Mistakes

Using one factor for all analytes

The factor depends on molar mass. Applying glucose's 18.02 to cholesterol (which needs 38.67) gives a badly wrong value.

Mismatching value and range units

Comparing an mmol/L value against an mg/dL reference range (or vice versa) misjudges whether a result is normal.

Confusing the conversion direction

mg/dL is divided by the factor to get mmol/L; multiplied to go back. Reversing it inverts the result.

Over-precise reporting

Lab measurements have limited precision. Excess decimal places in a converted value overstate the certainty.

Why Clinical Concentration Conversion Matters

Blood test results travel between countries and references that use different unit systems — mg/dL in the US, mmol/L almost everywhere else — so interpreting a glucose or cholesterol value often means converting first. Because the conversion depends on each substance's molar mass, using the wrong factor produces a value that looks plausible but is clinically misleading.

For people managing diabetes or cardiovascular risk, and for clinicians comparing results across systems, accurate, analyte-specific conversion is essential to tracking trends and applying the right reference ranges. This converter provides those factors as an educational and reference aid; the clinical meaning of any result should always be discussed with a qualified healthcare professional.

Built for patients tracking lab values, healthcare students, and clinicians converting glucose and cholesterol between mg/dL and mmol/L.

Linear unit factors follow the BIPM SI brochure, the NIST Guide to the SI, and ISO 80000. Currency rates load live from open.er-api.com; crypto prices from CoinGecko. See our methodology and editorial policy. Educational only — not certified for regulated trading, settlement, medical, or aerospace use.

Clinical Concentration Converter FAQs

Divide the mg/dL value by 18.0182 to get mmol/L. So a fasting glucose of 90 mg/dL is about 5.0 mmol/L, and the diabetes threshold of 126 mg/dL is 7.0 mmol/L. To go back, multiply mmol/L by 18.0182. The factor comes from glucose's molar mass and applies only to glucose.

Because converting between mass concentration (mg/dL) and molar concentration (mmol/L) requires the substance's molar mass. Glucose (molar mass ~180 g/mol) uses a factor of 18.02, while cholesterol (~387 g/mol) uses 38.67. Using one substance's factor for another gives an incorrect result.

Divide the mg/dL value by 38.67 to get mmol/L. So a total cholesterol of 200 mg/dL is about 5.17 mmol/L, and 240 mg/dL (high) is about 6.21 mmol/L. The same factor applies to LDL and HDL cholesterol, but triglycerides use a different factor (about 88.57).

mg/dL (milligrams per decilitre) measures the mass of a substance per tenth of a litre of blood and is used mainly in the US. mmol/L (millimoles per litre) measures the number of molecules per litre and is the SI standard used in most of the world. Converting between them requires the substance's molar mass.

No. It's an educational and reference tool for converting units. The clinical meaning of any lab value — whether it's normal, what it implies, and what to do — depends on your full health picture and must be interpreted by a qualified healthcare professional. Use the conversion to understand a number, not to self-diagnose.

It uses each analyte's standard molar-mass-derived factor (glucose 18.0182, cholesterol 38.67, and so on) and computes at full precision, so the unit conversion is mathematically exact to your input precision. Clinical interpretation, however, depends on factors beyond the conversion and requires professional judgement.