Blood Glucose Reporting in mmol/L
To convert blood glucose readings from mg/dL to mmol/L, multiply by 0.0555 or divide by 18 1.
Key Conversion Values
The following standardized conversions should be used when reporting glucose values in mmol/L 1, 2:
- 12 mg/dL = 0.67 mmol/L
- 15 mg/dL = 0.83 mmol/L
- 75 mg/dL = 4.16 mmol/L
- 100 mg/dL = 5.56 mmol/L
Diagnostic and Target Thresholds in mmol/L
When reporting glucose values for diagnosis and management, use these established thresholds 2:
Diagnostic Criteria
- Fasting plasma glucose >7.0 mmol/L (>126 mg/dL) is diagnostic of diabetes
- Screening thresholds:
- Normal fasting glucose: <5.6 mmol/L (<100 mg/dL)
- Impaired fasting glucose: 5.6-6.9 mmol/L (100-125 mg/dL)
- 2-hour OGTT normal: <7.8 mmol/L (<140 mg/dL)
Target Ranges for Monitoring
- Standard target range: 4-10 mmol/L (72-180 mg/dL) 3
- Hypoglycemia threshold: <3.9 mmol/L (<70 mg/dL) 4
- Hyperglycemia threshold: >7.8 mmol/L (>140 mg/dL) 4
Practical Considerations
Meter Accuracy Standards
When converting accuracy specifications for glucose meters to mmol/L 1:
- Hospital-use meters must achieve 95% of readings within 0.67 mmol/L (12 mg/dL) at low glucose concentrations
- Home-use meters must achieve 95% of readings within 0.83 mmol/L (15 mg/dL) at low glucose concentrations
CGM Device Limits
Continuous glucose monitors typically report values within 2.2-22.2 mmol/L (40-400 mg/dL), with readings outside this range being "capped" at the boundary values 5.
Normal Reference Values
In healthy non-diabetic individuals, mean glucose is approximately 5.4-5.5 mmol/L (98-99 mg/dL), with 96% of time spent between 3.9-7.8 mmol/L (70-140 mg/dL) 4.