- Choose the conversion direction — HbA1c → eAG, or eAG → HbA1c.
- If converting from eAG, select the glucose unit (mg/dL or mmol/L) to match how the value was reported.
- Enter the known value. The result updates live — no button needed.
- Read eAG in both mg/dL and mmol/L plus the derived HbA1c and the glycemic category.
- In advanced CKD and dialysis, read the caution panel first — HbA1c may not reflect true glycemia, and the conversion can mislead.
All computation runs in your browser; no values are stored or transmitted.
When to Use
Use this converter to translate an HbA1c (%) into an estimated average glucose (eAG) — the same units a patient sees on a home glucose meter or continuous glucose monitor — or to back-calculate the HbA1c an average glucose corresponds to. The eAG framing (Nathan/ADAG, 2008) helps patients relate a lab A1c to the numbers they check at home, and helps clinicians sanity-check whether a measured A1c is consistent with a patient's glucose logs.
Appropriate use
Patient education and target-setting in people with reliable red-cell turnover — explaining what an A1c "means" in glucose units, and comparing eAG to self-monitored or CGM averages. The glycemic category band (normal / prediabetes / diabetes) and the individualized target reminders apply to the general population.
When the conversion is unreliable
In advanced CKD (especially CKD G5 and dialysis), the A1c↔eAG relationship breaks down. HbA1c reflects red-cell lifespan as much as glucose, and uremia distorts the assay. Do not anchor management to a single A1c-derived eAG in dialysis patients — prefer CGM/time-in-range, glycated albumin, or fructosamine, and individualize targets. See the caution panel in the calculator.
Pearls & Pitfalls
eAG speaks the patient's language
An A1c of 7% is abstract; "your average glucose is about 154 mg/dL (8.6 mmol/L)" maps directly onto a glucometer. Use eAG to make targets concrete and to spot discordance — if the eAG is far from the patient's logged averages, question the A1c, the meter technique, or the red-cell biology.
Why A1c runs FALSELY LOW in CKD/dialysis
Shortened red-cell lifespan and hemolysis, ESA (erythropoietin) therapy and iron repletion that flood the circulation with young red cells, and recent blood transfusions all reduce the fraction of hemoglobin that has had time to glycate — so the measured A1c underestimates true average glucose. A "reassuring" A1c in a dialysis patient may hide real hyperglycemia.
Why A1c can also run FALSELY HIGH — and the bottom line
Carbamylated hemoglobin from uremia, metabolic acidosis, and certain assay interferences can raise measured A1c independent of glucose. The net direction in any individual is unpredictable. Bottom line: in dialysis the meter/CGM average is more trustworthy than A1c — confirm with CGM (time-in-range), glycated albumin, or fructosamine and individualize targets.
Why Use It
The ADAG study (Nathan 2008) established a linear, clinically usable relationship between A1c and mean glucose, giving the eAG concept now embedded in ADA Standards of Care. eAG improves patient understanding and shared decision-making. But the same study population had normal red-cell kinetics — which is exactly what kidney failure disrupts. Pairing the convenient conversion with an explicit CKD/dialysis caveat keeps clinicians from over-trusting an A1c that the kidney has quietly biased, and steers them toward CGM, glycated albumin, or fructosamine when the stakes are high.
eAG ↔ HbA1c Converter — with CKD/dialysis caveats
Choose a direction and enter a value to convert between HbA1c (%) and estimated average glucose (eAG). Results show eAG in both mg/dL and mmol/L, the derived HbA1c, and the glycemic category. Read the CKD caution before applying results to dialysis patients.
HbA1c is unreliable in advanced CKD & dialysis
Often falsely LOW: shortened red-cell lifespan, hemolysis, ESA (erythropoietin) and iron therapy (more young red cells), and transfusions all pull A1c down — masking true hyperglycemia. Sometimes falsely HIGH: carbamylated hemoglobin (uremia), acidosis, and assay interference. Net: the A1c↔eAG conversion is unreliable in dialysis. Prefer CGM / time-in-range, glycated albumin, or fructosamine, interpret A1c with caution, and individualize targets (often 7–8% in frail or dialysis patients). For a patient, the home meter / CGM average is more trustworthy than A1c here.
⚕ ADAG (Nathan 2008): eAG (mg/dL) = 28.7 × A1c − 46.7; eAG (mmol/L) = 1.59 × A1c − 2.59; A1c (%) = (eAG mg/dL + 46.7) / 28.7. eAG and a lab glucose are not identical measurements. Conversion assumes normal red-cell kinetics and is unreliable in advanced CKD/dialysis. Educational aid — not a substitute for clinical judgment or CGM/glycated-albumin assessment. Source: Nathan DM, et al. Diabetes Care. 2008;31(8):1473–1478.
Next Steps
Use eAG to inform — not replace — clinical judgment.
- Compare the eAG to the patient's self-monitored or CGM glucose averages; large discordance suggests a biased A1c, meter error, or altered red-cell biology.
- In CKD G4–G5 and dialysis, do not anchor targets to A1c alone — obtain CGM/time-in-range, glycated albumin, or fructosamine.
- Individualize glycemic targets: generally A1c <7%, but 7–8% in frailty, limited life expectancy, hypoglycemia risk, or dialysis.
- Document the glycemic category and the reason for any relaxed target; coordinate with endocrinology and nephrology where complex.
Evidence & References
Formula & Equations
| Quantity | Equation (ADAG, Nathan 2008) |
|---|---|
| eAG (mg/dL) from A1c | 28.7 × A1c(%) − 46.7 |
| eAG (mmol/L) from A1c | 1.59 × A1c(%) − 2.59 |
| A1c (%) from eAG | (eAG mg/dL + 46.7) ÷ 28.7 |
| Glucose unit conversion | mg/dL = mmol/L × 18.0156 |
Reference values
| HbA1c (%) | eAG (mg/dL) | eAG (mmol/L) | Category / note |
|---|---|---|---|
| < 5.7 | < 117 | < 6.5 | Normal |
| 5.7 – 6.4 | 117 – 137 | 6.5 – 7.6 | Prediabetes |
| 6.5 | 140 | 7.8 | Diabetes threshold |
| 7.0 | 154 | 8.6 | Common general target (<7%) |
| 8.0 | 183 | 10.2 | Upper individualized target (CKD/frail, 7–8%) |
eAG values rounded. Targets are individualized; in advanced CKD and dialysis A1c may not reflect true glycemia — confirm with CGM/time-in-range, glycated albumin, or fructosamine.
Evidence & References
The ADAG study derived the linear A1c-to-mean-glucose relationship used for eAG. KDIGO's 2022 Diabetes-in-CKD guideline details the limitations of A1c in CKD/dialysis and supports CGM and time-in-range. ADA Standards of Care define the eAG concept and individualized glycemic targets.
- Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ; A1c-Derived Average Glucose (ADAG) Study Group. Translating the A1C Assay Into Estimated Average Glucose Values. Diabetes Care. 2008;31(8):1473–1478.
- Kidney Disease: Improving Global Outcomes (KDIGO) Diabetes Work Group. KDIGO 2022 Clinical Practice Guideline for Diabetes Management in Chronic Kidney Disease. Kidney Int. 2022;102(5S):S1–S127.
- American Diabetes Association Professional Practice Committee. Standards of Care in Diabetes — Glycemic Targets and Assessment of Glycemia. Diabetes Care (annual Standards of Care).
