What is the conversion factor between mg/dL and mmol/L for glucose?

The factor is 18.018, derived from the molar mass of glucose (180.16 g/mol). To go from mg/dL to mmol/L, divide by 18.018. To go from mmol/L to mg/dL, multiply by 18.018.

Which countries use which unit?

The United States, Germany, France, Japan, and several others use mg/dL. The United Kingdom, Canada, Australia, and most of Europe use mmol/L. The molecule is identical; only the unit differs.

What is a normal fasting glucose in each unit?

A normal fasting glucose is roughly 70–100 mg/dL, which equals about 3.9–5.6 mmol/L. Values of 126 mg/dL (7.0 mmol/L) or above on fasting are diagnostic of diabetes.

Is this the same as HbA1c?

No. This tool converts a single glucose reading, not HbA1c. HbA1c reflects average glucose over 2–3 months and uses its own units (% or mmol/mol), which require a different conversion.

Is my data stored anywhere?

No. The conversion runs entirely in your browser and the value you enter is never transmitted to or saved on any server.

Blood Glucose Unit Converter (mg/dL to mmol/L)

The Blood Glucose Unit Converter switches a blood-sugar reading between the two unit systems used worldwide: mg/dL (milligrams per decilitre, used in the US, Germany, France, and Japan) and mmol/L (millimoles per litre, used in the UK, Canada, Australia, and most of Europe). The molecule is identical — only the way it is reported changes.

How it works

Glucose has a molar mass of about 180.16 g/mol. Converting a mass concentration (mg/dL) to a molar concentration (mmol/L) uses this constant:

mmol/L = mg/dL ÷ 18.018

mg/dL = mmol/L × 18.018

The factor 18.018 comes from 180.16 ÷ 10, accounting for the per-decilitre versus per-litre difference. For example, a meter reading of 100 mg/dL equals 100 ÷ 18.018 ≈ 5.6 mmol/L.

Reference values and notes

A normal fasting glucose is roughly 70–100 mg/dL (3.9–5.6 mmol/L). A fasting value of 126 mg/dL (7.0 mmol/L) or higher is a diagnostic threshold for diabetes, while 200 mg/dL (11.1 mmol/L) is a common random/post-load threshold.

This tool converts a single point-in-time reading and is not the same as HbA1c, which summarises average glucose over months and uses its own units. Always interpret converted values against the reference ranges of your own laboratory and clinical guidelines.