HEALTH · BLOOD SUGAR CONVERTER

Blood Sugar Converter

Convert blood glucose between mg/dL and mmol/L, and convert A1C to estimated average glucose (eAG) or vice versa. For informational use only.

Conversion Type
Input Value

Normal fasting: 70–99 mg/dL

01 Glucose Conversion
mg/dL100 mg/dL
mmol/L5.5 mmol/L

About This Calculator

The blood sugar converter handles two distinct conversions: (1) glucose unit conversion between mg/dL and mmol/L — the two dominant measurement systems used globally — and (2) A1C percentage to estimated average glucose (eAG) and back, using the ADAG formula (Nathan et al., Diabetes Care 2008). This is a conversion tool only; it does not produce clinical risk assessments. For A1C risk categories, see the A1C Calculator.

How It Works

For glucose conversion: mg/dL and mmol/L are related by glucose's molecular weight of 180.182 g/mol. Multiply mg/dL by 1/18.0182 to get mmol/L; multiply mmol/L by 18.0182 to get mg/dL. For A1C ↔ eAG: the ADAG study (2008) established that eAG (mg/dL) = 28.7 × A1C(%) − 46.7. This formula was validated across multiple populations and is endorsed by the ADA, EASD, and IDF. Select the conversion direction and enter your value.

The Formula

mmol/L = mg/dL ÷ 18.0182 | eAG (mg/dL) = 28.7 × A1C% − 46.7

mg/dL
milligrams of glucose per deciliter of blood
mmol/L
millimoles of glucose per liter of blood
A1C%
glycated hemoglobin percentage (4–20% validated range)
eAG
estimated average glucose — 3-month mean blood glucose approximation

Frequently Asked Questions

What is the difference between mg/dL and mmol/L?
Both measure the concentration of glucose in blood, but use different unit systems. mg/dL (milligrams per deciliter) is standard in the United States. mmol/L (millimoles per liter) is used in most other countries. The conversion factor is 18.0182, derived from glucose's molecular weight of 180.182 g/mol. A value of 100 mg/dL equals approximately 5.6 mmol/L.
What does eAG tell me?
eAG (estimated average glucose) expresses the average blood glucose level implied by an A1C result, in the same mg/dL or mmol/L units you see on a glucose meter. An A1C of 7.0% corresponds to an eAG of approximately 154 mg/dL (8.6 mmol/L), according to the ADAG formula. This can be easier to interpret than a percentage alone.
Is this the same as the A1C Calculator?
No — the A1C Calculator maps an A1C percentage to clinical risk categories (normal, prediabetes, diabetes) per ADA guidelines. This blood sugar converter is a pure unit conversion tool — it converts between measurement units without making clinical judgments. Both are informational only; consult a healthcare provider for diagnosis.
What are normal blood glucose ranges?
For reference only (not a diagnostic tool) — fasting glucose for non-diabetic adults is generally 70–99 mg/dL (3.9–5.5 mmol/L). An A1C below 5.7% is considered normal. These thresholds may differ for specific clinical contexts; your healthcare provider is the authority on your individual values.