mg/dL to mmol/L Converter

mg/dL

mmol/L

Common Conversions

mg/dL	mmol/L
1	10/MW
5	50/MW
10	100/MW
50	500/MW
100	1000/MW
200	2000/MW
300	3000/MW
500	5000/MW
1000	10000/MW
2000	20000/MW
5000	50000/MW
10000	100000/MW

Why this conversion matters in chemistry

Clinical chemistry is split between two unit conventions for the same measurements. The US reports plasma glucose, cholesterol, creatinine, and most metabolites in mg/dL. International reference ranges, ADA-EASD guidelines, and most journals outside the US use mmol/L. The conversion is mass to moles through the analyte's molar mass, with a factor of 10 to handle the step from deciliters to liters. A 100 mg/dL fasting glucose works out to 5.55 mmol/L (glucose at 180.16 g/mol). The factor that comes up most often — for glucose specifically — is 18.016: dividing mg/dL by 18.016 gives mmol/L directly.

Formula

mmol/L = (mg/dL × 10) / MW

Worked Examples

100 mg/dL (glucose, MW 180.16) = 5.55 mmol/L

A normal fasting plasma glucose — the conversion that comes up in every diabetes-related metabolic conversation.

126 mg/dL (glucose) = 7.0 mmol/L

The fasting-glucose diagnostic threshold for diabetes in both ADA and WHO criteria.

200 mg/dL (cholesterol, MW 386.65) = 5.17 mmol/L

The borderline-high total cholesterol cutoff in US guidelines, expressed in SI units for international reporting.

1.0 mg/dL (creatinine, MW 113.12) = 0.0885 mmol/L

A normal serum creatinine — equivalently 88.5 µmol/L in the units most international clinical labs actually report.

Frequently Asked Questions

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

Multiply by 10 to handle the step from deciliters to liters, then divide by the molar mass. For glucose at 180.16 g/mol, 100 mg/dL becomes (100 × 10) / 180.16 = 5.55 mmol/L.

Why do different countries use different units?

The US clinical convention is mass concentration in mg/dL; most international reporting is molar concentration in mmol/L. SI recommends molar units, so peer-reviewed publications and international guidelines have largely moved to mmol/L.

What's the shortcut for glucose?

Divide mg/dL by 18.016 to get mmol/L. The 18.016 is glucose's molar mass divided by 10 — packaged so you don't need to remember to multiply by 10 first. So 100 mg/dL / 18.016 = 5.55 mmol/L.