A1C to Average Glucose Calculator (eAG)
Convert HbA1c to estimated average glucose (mg/dL, mmol/L) and back. Free, private and instant.
How to use the A1C Calculator
- Choose convert: A1C (%) to average glucose or Average glucose to A1C (%).
- Choose glucose unit: mg/dL or mmol/L.
- Answer any extra questions that appear for your choices.
- Press Calculate to get an instant result with a colour scale, chart and plain-English explanation.
About the A1C Calculator
Haemoglobin A1C (HbA1c) is the share of haemoglobin in your red blood cells that has glucose attached, which reflects your average blood sugar over the past 2 to 3 months. This calculator converts A1C to estimated average glucose (eAG) using the ADAG study formula adopted by the American Diabetes Association, converts glucose back to A1C, and also shows the IFCC value in mmol/mol used on UK and European lab reports.
Also known as: A1C calculator, HbA1c to eAG, A1C to blood sugar converter, estimated average glucose calculator, HbA1c mmol/mol converter.
Worked example
- Convert: A1C (%) to average glucose
- HbA1c: 7%
- Glucose unit: mg/dL
Estimated average glucose: 154 mg/dL (Diabetes range). An A1C of 7.0% means your blood glucose has averaged about 154 mg/dL (8.6 mmol/L) over the last 2 to 3 months.
- A1C (NGSP): 7.0 %
- A1C (IFCC): 53 mmol/mol
- Average glucose: 154 mg/dL
- Average glucose: 8.6 mmol/L
Formula and cut-offs
eAG (mg/dL) = 28.7 x A1C - 46.7. eAG (mmol/L) = eAG (mg/dL) / 18. IFCC A1C (mmol/mol) = (A1C % - 2.15) x 10.929. ADA ranges: below 5.7% normal, 5.7-6.4% prediabetes, 6.5% or above diabetes.
Frequently asked questions
What average blood sugar is an A1C of 7%?
An A1C of 7% matches an estimated average glucose of about 154 mg/dL (8.6 mmol/L). Each 1% rise in A1C adds about 29 mg/dL (1.6 mmol/L) to average glucose.
What is a normal A1C?
Below 5.7% (39 mmol/mol) is normal. 5.7% to 6.4% (39-47 mmol/mol) is the prediabetes range, and 6.5% (48 mmol/mol) or higher on two tests indicates diabetes.
Why does my meter average differ from my A1C?
Finger-stick readings are snapshots, often taken before meals, while A1C reflects all hours of the day. Anaemia, kidney disease, pregnancy and haemoglobin variants can also shift A1C.
How often should A1C be checked?
People with diabetes usually have A1C checked every 3 to 6 months. Adults without diabetes are screened less often, depending on age and risk factors.
What is the estimated average glucose for an HbA1c of 7%?
Estimated average glucose: 154 mg/dL (Diabetes range). An A1C of 7.0% means your blood glucose has averaged about 154 mg/dL (8.6 mmol/L) over the last 2 to 3 months. Enter your own numbers above for a personal result.
Sources and references
- Nathan DM et al. Translating the A1C assay into estimated average glucose values. Diabetes Care 2008
- National Kidney Foundation - eGFR calculator and CKD staging
- NHS - Chronic kidney disease
Written and checked by the MediHub editorial team against the sources above. Read how we build and review our calculators.
More health calculators
- Drug Half-Life Calculator
- Medication Days Supply and Refill Date Calculator
- Medicine Treatment Cost Comparator
- eGFR Calculator (CKD-EPI 2021)
- Body Mass Index (BMI) Calculator
- Daily Calorie Needs Calculator
- More Medication & lab results calculators
- All health calculators
- Compare medicine prices in 32 countries
Last updated . This calculator is for education only and is not medical advice. See the medical disclaimer.