If you have results from labs in different countries, the units can be confusing. US labs typically report conventional units like mg/dL, while labs across Europe use SI units like mmol/L. Here is how they relate.
Two systems, one result
Conventional units (mg/dL) measure mass per volume; SI units (mmol/L) measure amount of substance per volume. Converting between them uses a fixed factor per biomarker — for glucose, mg/dL is about 18 times the mmol/L value.
So a fasting glucose of 90 mg/dL in the US is about 5.0 mmol/L in Europe. The health meaning is identical; only the scale differs.
Common conversions
Glucose: mmol/L x 18 = mg/dL. Total cholesterol: mmol/L x 38.67 = mg/dL. These factors are biomarker-specific, so you cannot apply one factor across all tests.
BloodId stores each value in the units your lab reported and converts at display time, so results from a US lab and a European lab line up on the same chart without manual math.
Frequently asked questions
Is mg/dL or mmol/L better?
Neither — they are just different unit systems. The US uses mg/dL; most of Europe uses mmol/L. The same result can be expressed in either.
How do I convert glucose from mmol/L to mg/dL?
Multiply the mmol/L value by about 18. For example, 5.0 mmol/L is roughly 90 mg/dL. The conversion factor is different for each biomarker.
Can I compare results from labs in different countries?
Yes. Convert both to the same unit, or use a tool like BloodId that stores each value in its original units and normalizes them at display time.