A1C to Average Blood Sugar
Convert HbA1c (%) or IFCC (mmol/mol) to estimated average glucose. You enter the lab number.
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
You have
ADA conversion: eAG mg/dL = 28.7 x A1C - 46.7. Screening cut-offs: under 5.7% usual, 5.7 to 6.4% prediabetes range, 6.5%+ diabetes range. A lab result still needs a clinician.
Estimates only. Not medical advice and not a diagnosis. Talk to a clinician about your own numbers. Do not change medication from this page.
About this tool
HbA1c is a lab measure of average blood glucose over roughly three months. You type the number from your own report; nothing is measured on this page. The ADA conversion used here is eAG (mg/dL) = 28.7 times A1C percent minus 46.7. Screening cut-offs often quoted are under 5.7% usual, 5.7 to 6.4% prediabetes range, and 6.5% or higher diabetes range. Those bands do not diagnose you from a website. Trends, symptoms and other labs matter. Estimates only. Not medical advice and not a diagnosis. Do not change medication from this calculator.
How to use this tool
- Choose A1C %, mmol/mol or eAG mg/dLUse the units printed on your lab report. Switching units keeps the same underlying percent.
- Type the numberConversion and the screening band update immediately.
- Take the printout to a clinicianA website band is not a diagnosis. Do not change tablets or insulin from this page.
How to convert A1C to average blood sugar
The ADA formula is: estimated average glucose (mg/dL) = 28.7 x A1C - 46.7. An A1C of 7% therefore matches an average of about 154 mg/dL, or 8.6 mmol/L. To convert A1C from percent to mmol/mol, subtract 2.15 and multiply by 10.929: 7% is 53 mmol/mol.
A1C reflects roughly the last three months, so it will not match a single finger-prick reading. Use it to understand your own lab results, and talk to your doctor about what your numbers mean for you.
Key features
- ADA eAG in mg/dL and mmol/L from NGSP percent.
- IFCC mmol/mol conversion both ways.
- Reverse from estimated average glucose if that is what you have.
- Clear screening labels that still say they are not a diagnosis.
Common uses
- Translating a 7% A1C into an estimated average glucose around 154 mg/dL.
- Matching a US percent report with a European mmol/mol report.
- Understanding a number before an appointment, not instead of one.
Tips for better results
- Use the same lab method when you compare two dates. NGSP percent and IFCC mmol/mol are different scales.
- Anaemia, kidney disease and some haemoglobin variants can skew A1C. A clinician knows when to use another test.
- Glucometer averages are not the same as eAG from A1C, but they should be in the same neighbourhood.
Mistakes to avoid
- Calling this page a diagnosis of diabetes or prediabetes.
- Changing insulin or tablets because the converter showed a high eAG.
- Mixing mmol/mol (A1C) with mmol/L (glucose).
- Ignoring symptoms because a single A1C sat under 5.7%.
Frequently asked questions
eAG mg/dL = 28.7 x A1C minus 46.7. Divide mg/dL by 18.0182 for mmol/L. That is the ADA estimate, not a glucometer reading. A1C 7% is about 154 mg/dL.
Labs and guidelines often use 6.5% or higher as a diabetes screening cut-off, with confirmation rules. Only a clinician diagnoses.
No. mmol/mol is IFCC HbA1c. mmol/L is glucose. This page converts both ways so you can match your report.
No. You enter a number you already have. There is no test kit and no upload of a lab PDF.
Guidelines often suggest about twice a year for people meeting their targets and every three months when treatment changes or targets are not met. Your doctor sets the schedule that fits your situation.
A1C reflects roughly three months of glucose, weighted toward the most recent weeks, while finger-stick readings are snapshots. Anaemia and some other conditions also shift A1C, so differences are worth discussing with your clinician.
Use mmol/mol = (A1C% - 2.15) x 10.929. A1C of 6.5% is 48 mmol/mol and 7% is 53 mmol/mol; the UK and much of Europe report in mmol/mol.