Blood Glucose mmol/L to mg/dL Calculator and Conversion Chart
Blood Glucose mmol/L to mg/dL Calculator
Convert blood sugar from mmol/L to mg/dL instantly—or enter mg/dL to see the mmol/L equivalent. Includes a quick conversion chart for common glucose readings.
Common unit in the UK, Canada and many other countries.
Common unit in the United States and some other countries.
Blood glucose mmol/L to mg/dL conversion chart
For a quick answer: 5.5 mmol/L equals about 99 mg/dL, while 100 mg/dL equals about 5.6 mmol/L. The chart below rounds to practical whole-number mg/dL values.
| Blood glucose (mmol/L) | Blood glucose (mg/dL) |
|---|---|
| 3.9 | 70 |
| 4.0 | 72 |
| 5.0 | 90 |
| 5.5 | 99 |
| 6.0 | 108 |
| 7.0 | 126 |
| 8.0 | 144 |
| 10.0 | 180 |
| 11.1 | 200 |
| 13.9 | 250 |
| 16.7 | 300 |
How to use the blood sugar converter
- Look at the unit beside your result: mmol/L or mg/dL.
- Enter only the number into the corresponding box at the top of this page.
- The reverse conversion appears instantly.
- Keep the original unit and the timing of the reading when discussing it with a clinician or diabetes team.
This calculator uses the standard glucose conversion: mg/dL = mmol/L × 18.0182. To convert back, divide mg/dL by 18.0182. For everyday reading, it is usually sensible to round mmol/L to one decimal place and mg/dL to the nearest whole number.
Why are blood glucose units different?
Blood glucose and blood sugar mean the same thing in this context: the amount of glucose circulating in the blood. In the UK, laboratory reports, finger-prick meters and continuous glucose-monitoring systems generally display glucose in millimoles per litre (mmol/L). In the United States, results are commonly shown in milligrams per decilitre (mg/dL).
The two units describe the same concentration. A conversion can be useful if you are reading an overseas diabetes forum, using a device set to another region, looking at research papers, or comparing information from different countries.
Blood glucose is not the same as HbA1c
Blood glucose is a reading at one point in time. It can change with food, exercise, illness, stress, sleep, alcohol, medicines and the time of day. HbA1c is a different blood test that reflects longer-term average glucose exposure over roughly two to three months. If you are comparing a glucose reading with an HbA1c report, use the correct unit and test type—one cannot be directly substituted for the other.
Why timing matters when interpreting a result
A number alone does not tell the full story. A fasting laboratory glucose test is interpreted differently from a reading taken after a meal. A home finger-prick meter and a continuous glucose monitor are also useful in different ways, but their readings should not be used to self-diagnose. If you have diabetes, use the personal plan and targets agreed with your own clinical team.
If you do not have diabetes but have had a result that concerns you, the safest next step is to speak to your GP or the clinician who arranged the test. For general information about diabetes, see the NHS diabetes guidance.
Frequently asked questions
What is 5.5 mmol/L in mg/dL?
5.5 mmol/L is approximately 99 mg/dL.
What is 100 mg/dL in mmol/L?
100 mg/dL is approximately 5.6 mmol/L.
What is 7 mmol/L in mg/dL?
7.0 mmol/L is approximately 126 mg/dL.
Do I multiply mmol/L by 18 to get mg/dL?
Yes. For glucose, multiplying mmol/L by about 18 gives an everyday mg/dL conversion. This calculator uses the more precise factor of 18.0182.
Can this calculator tell me whether I have diabetes?
No. A conversion changes the units only. Diagnosis depends on the correct test, timing, repeat testing where appropriate, symptoms and clinical assessment.
Are home glucose meter results exact?
Home meters are useful monitoring tools, but readings can vary. Follow your device instructions and seek clinical advice about unexpected or concerning readings.
Sources and further reading
Support Pryhelm
Buying through our eBay shop helps support free practical health calculators and guides.
Visit the Pryhelm eBay shop