🧪 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.