154.2
mg/dL
8.57
mmol/L
0
%
0
mg/dL
28.7
mg/dL
154.2
mg/dL
8.57
mmol/L
0
%
0
mg/dL
28.7
mg/dL
The Estimated Average Glucose (eAG) Calculator translates your HbA1c lab result into the average blood glucose level you would see on a glucose meter, making it easier to understand what your A1c number actually means in practical terms. The eAG concept was introduced to bridge the communication gap between the laboratory HbA1c percentage and the glucose numbers patients monitor daily.
HbA1c is reported as a percentage — for example, 7.0% — which, while medically meaningful, is not intuitively connected to the glucose readings patients see on their meters. The eAG converts this percentage into familiar units: an HbA1c of 7.0% corresponds to an average glucose of approximately 154 mg/dL (8.6 mmol/L). This translation helps patients and clinicians communicate more effectively about glucose management.
The ADAG (A1C-Derived Average Glucose) study, published by Nathan et al. in Diabetes Care (2008), established the definitive relationship between HbA1c and average glucose using data from 507 participants who wore continuous glucose monitors (CGMs) for weeks while simultaneously having HbA1c measured. The resulting linear equation — eAG = 28.7 × A1c − 46.7 — showed strong correlation (R² = 0.84) and has been adopted by the ADA, EASD, and most professional diabetes organizations worldwide.
Understanding your eAG also provides context for your daily glucose readings. If your eAG is 154 mg/dL, you would expect to see daily readings typically ranging from about 124 to 184 mg/dL, with normal fluctuations around the average. Readings consistently above the eAG + 30 range may indicate post-meal spikes, while readings consistently below the eAG − 30 range may indicate hypoglycemic episodes.
The eAG is now routinely reported alongside HbA1c on laboratory results in many healthcare systems. This calculator provides the conversion instantly and classifies the result by glycemic status — from normal through prediabetes to various levels of diabetic control. It is an essential tool for anyone managing diabetes or at risk for the condition.
The eAG is calculated using the ADAG study formula:
eAG (mg/dL) = 28.7 × HbA1c (%) − 46.7
eAG (mmol/L) = eAG (mg/dL) / 18.0156
The typical daily glucose range is estimated as eAG ± 30 mg/dL, reflecting normal intraday variation including fasting lows and postprandial peaks.
Glycemic status: 1 = Normal (A1c <5.7%), 2 = Prediabetes (5.7-6.4%), 3 = Well-controlled diabetes (6.5-6.9%), 4 = Fair control (7.0-7.9%), 5 = Poor control (≥8.0%).
The eAG value represents what your blood sugar has been, on average, over the past 2-3 months. The typical daily range shows the expected low and high glucose values you might see between meals and after meals. If your daily readings fall consistently outside this range, discuss adjustments with your healthcare provider. Remember that eAG is an average — it does not capture glucose variability. Two people with the same eAG can have very different daily patterns (one stable, one swinging between highs and lows).
Inputs
Results
HbA1c 6.8% corresponds to eAG of ~149 mg/dL. Well-controlled. Expected daily range 119-179 mg/dL.
Inputs
Results
HbA1c 9.5% means an average glucose of ~226 mg/dL. Poor control with high complication risk.
eAG translates your HbA1c percentage into the glucose units (mg/dL or mmol/L) you see on your meter. It represents your average blood sugar over 2-3 months. For example, an A1c of 7% means your glucose averaged about 154 mg/dL.
eAG bridges the gap between lab percentages and daily glucose readings. Telling a patient their A1c is 8.0% is less intuitive than saying their average blood sugar has been about 183 mg/dL. eAG makes the clinical goal more relatable and actionable.
No. Fasting glucose is a single point-in-time measurement after 8+ hours without food. eAG is the 24-hour average over months, including fasting, pre-meal, post-meal, and overnight glucose values. eAG is always higher than fasting glucose because it includes postprandial spikes.
The ADAG formula has an R² of 0.84, meaning it explains 84% of the variance between A1c and glucose. Individual variation exists — factors like red blood cell lifespan, hemoglobin variants, and glucose variability mean the true average may differ by ±15 mg/dL from the calculated eAG.
No. eAG provides the long-term average but cannot show daily patterns, post-meal spikes, overnight lows, or glucose variability. Daily monitoring (fingerstick or CGM) is still essential for immediate treatment decisions, meal planning, and exercise adjustments.
For most adults with diabetes, the ADA target A1c of <7% corresponds to an eAG below 154 mg/dL. Your doctor may set a different target based on age, complication risk, and hypoglycemia history. Discuss your personal target during your next appointment.
Two patients can have the same eAG of 154 mg/dL with very different patterns. One may be steady at 130-180 mg/dL while another swings between 60-250 mg/dL. The second patient faces higher complication risk despite the same average. CGM provides Time-in-Range metrics that capture this variability.
Yes and no. Frequent hypoglycemia can actually lower the average and produce a misleadingly good eAG/A1c. This is why eAG should not be the sole metric — clinicians should also assess hypoglycemia frequency and Time Below Range (<70 mg/dL) using CGM or glucose log data.
The ±30 mg/dL range is a rough estimate. Actual glycemic variability depends on diet, medication, exercise, and individual physiology. CGM data shows that most people with diabetes have glucose readings spanning 60-80 mg/dL around their average. The provided range gives a general expectation.
Meter averages are biased by when you test. Most people test fasting (lower values) and skip post-meal readings (higher values). CGM averages tend to be higher than fingerstick averages because they capture all values. Your eAG reflects the true 24-hour average regardless of when you test.
Roboculator Team
The Roboculator Team explains calculations, planning tools, and practical formulas in clear language for real-life situations.
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