🧪 HbA1c Converter (%, IFCC & eAG)
HbA1c in NGSP % and IFCC mmol/mol are linked by IFCC = 10.929 × (% − 2.15); estimated average glucose is eAG = 28.7 × % − 46.7 mg/dL. Enter your values below, results update instantly, entirely on your device.
ADAG: eAG = 28.7 × A1C − 46.7
How the hba1c converter (%, ifcc & eag) works
The NGSP percentage and the IFCC value are related by IFCC (mmol/mol) = 10.929 × (NGSP% − 2.15), and the reverse NGSP% = IFCC ÷ 10.929 + 2.15. Estimated average glucose comes from the ADAG study: eAG (mg/dL) = 28.7 × NGSP% − 46.7, then eAG (mmol/L) = eAG (mg/dL) ÷ 18.0182.
Example: HbA1c 7% → IFCC 53 mmol/mol, and eAG = 28.7 × 7 − 46.7 = 154 mg/dL (8.6 mmol/L).
Since 2011 labs increasingly report HbA1c in IFCC mmol/mol alongside (or instead of) the older NGSP/DCCT percentage, so converting between the two is a common need. The estimated average glucose (eAG) puts HbA1c on the same scale as a day-to-day glucose meter using the ADAG regression. These are unit conversions and population estimates only, not medical advice, and not a diagnosis. Discuss what your HbA1c means with your clinician.
Frequently asked questions
How do I convert HbA1c % to mmol/mol?
Use IFCC = 10.929 × (NGSP% − 2.15). For example 7% gives 10.929 × 4.85 = 53 mmol/mol. To reverse it, NGSP% = mmol/mol ÷ 10.929 + 2.15.
What is eAG (estimated average glucose)?
A way to express HbA1c on the same scale as a glucose meter. eAG (mg/dL) = 28.7 × HbA1c% − 46.7, from the ADAG study, so 7% ≈ 154 mg/dL or 8.6 mmol/L.
What is the difference between NGSP and IFCC?
They measure the same glycated haemoglobin but on different scales: NGSP/DCCT reports a percentage (aligned to the original diabetes trials), while IFCC reports mmol of HbA1c per mol of haemoglobin. Many labs now show both.
Does a higher HbA1c always mean the same average glucose?
eAG is a population average, individual red-cell turnover varies, so two people with the same HbA1c can have somewhat different true average glucose. Treat eAG as an estimate and consult your clinician.
Is anything uploaded?
No, every calculation runs locally in your browser.
Is this hba1c converter (%, ifcc & eag) accurate and private?
Yes. It uses the standard published formula, shows its working under every result, and computes locally in your browser, your inputs are never sent to a server, and the page works offline.