eAG: What Your A1C Really Means in Everyday Numbers
Convert your HbA1c percentage into an average glucose you can understand — and compare to your meter.
Who is this especially useful for?
- ✓You have an A1c result and want to know what it means in practical terms
- ✓You monitor glucose daily and want to compare to your A1c
- ✓You're setting blood sugar goals and want them in familiar units
- ✓Your doctor mentioned A1c but you're not sure what the number means
eAG bridges the gap between lab results (A1c) and daily glucose monitoring.
HbA1c is a powerful measure of long-term blood sugar control. But what does "7.0%" actually mean in terms you encounter daily? That's where eAG comes in.
eAG (Estimated Average Glucose) translates your HbA1c percentage into an average blood sugar reading — the same units you see on a glucometer. It bridges the gap between lab results and daily glucose monitoring.
How to Find Your HbA1c
You need just one value:
HbA1c
Listed as "HbA1c", "Hemoglobin A1c", "A1C", or "Glycated Hemoglobin" on your lab report
HbA1c is reported as a percentage (%). If yours is reported in mmol/mol (IFCC), our calculator can convert it.
I have my HbA1c →What is eAG?
eAG stands for Estimated Average Glucose. It's a calculated value that converts your HbA1c (glycated hemoglobin) percentage into an equivalent average blood sugar level.
HbA1c reflects your average blood sugar over the past 2-3 months by measuring how much glucose has attached to your red blood cells. eAG takes that percentage and expresses it in mg/dL (or mmol/L) — the same units you'd see on a home glucose meter.
This was standardized by the American Diabetes Association (ADA) in 2008 based on the landmark ADAG study to help patients better understand what their A1c results mean in practical terms.
The Formula
eAG (mg/dL) = (28.7 × HbA1c) − 46.7
eAG (mmol/L) = (1.59 × HbA1c) − 2.59
Derived from the A1c-Derived Average Glucose (ADAG) Study • Our calculator handles all conversions
Example Calculation
HbA1c: 6.5%
eAG = (28.7 × 6.5) − 46.7 = 186.55 − 46.7 = 140 mg/dL
This means an A1c of 6.5% corresponds to an average glucose of about 140 mg/dL over the past 2-3 months
The Bridge Between Lab and Meter
Before eAG, patients received an A1c percentage that was hard to relate to their daily glucose readings. A patient with an A1c of 7.0% might wonder: "Is my average 150? 200?" eAG provides the answer — it's approximately 154 mg/dL.
507
Participants
In the landmark ADAG study
Nathan et al., 2008
r=0.92
Correlation
Between A1c and average glucose
ADAG Study
2008
ADA Standard
When formula was adopted
Diabetes Care
The research behind eAG
The A1c-Derived Average Glucose (ADAG) study followed 507 participants across 10 international centers, including individuals with type 1 diabetes, type 2 diabetes, and without diabetes.
Participants wore continuous glucose monitors (CGMs) and had frequent finger-stick tests for 3 months, allowing researchers to directly compare their measured average glucose to their A1c. The correlation was extremely strong (r = 0.92).
This research led the American Diabetes Association to recommend reporting eAG alongside A1c, making diabetes management more intuitive for patients worldwide.
Three Perspectives on eAG
Different health paradigms interpret glucose targets differently:
Standard Medical
ADA recommends A1c < 7% (eAG < 154 mg/dL) for most adults with diabetes.
Research Consensus
Functional medicine targets tighter glycemic control for disease prevention.
Metabolic Focus
Elevated average glucose often signals insulin resistance long before diabetes diagnosis.
HbA1c to eAG Conversion Table
| HbA1c | eAG | Status |
|---|---|---|
| 5.0% | 97 mg/dL | Non-diabetic |
| 5.7% | 117 mg/dL | Pre-diabetes threshold |
| 6.5% | 140 mg/dL | Diabetes threshold |
| 7.0% | 154 mg/dL | Common T2D target |
| 8.0% | 183 mg/dL | Above target |
| 9.0% | 212 mg/dL | High |
Why eAG and Your Meter May Differ
Don't expect perfect agreement between your meter average and eAG:
- •eAG = 24/7 average — includes overnight when glucose may be lower
- •Meter = spot checks — usually pre/post meals, may miss valleys
- •Fasting readings — typically lower than 24-hour average
- •Glycemic variability — high swings can produce different patterns than the average suggests
If your meter average is consistently 20+ mg/dL different from eAG, discuss testing timing and patterns with your healthcare provider.
Limitations to Consider
- •Individual variation — Some people run higher or lower glucose for the same A1c due to red blood cell lifespan differences
- •Conditions affecting A1c — Anemia, hemoglobin variants, kidney disease can affect accuracy
- •Not real-time — Reflects past 2-3 months, not current blood sugar
What If Your eAG Is High?
High eAG means your average blood sugar over the past 2-3 months has been elevated:
Lifestyle
- →Reduce carbohydrate intake
- →Increase physical activity
- →Spread carbs across meals
- →Avoid late-night eating
Medical
- →Discuss medications with your doctor
- →Consider CGM for real-time feedback
- →Retest A1c in 3 months
- →Check for underlying conditions
How Quickly Can eAG Improve?
Since A1c reflects 2-3 months of glucose control, meaningful changes in eAG require at least 3 months of sustained lifestyle or medication changes. The second half of this period contributes more to the A1c reading than the first.
Key Takeaways
- 1eAG converts HbA1c percentage to an average blood sugar in mg/dL (or mmol/L)
- 2Formula: eAG (mg/dL) = (28.7 × HbA1c) − 46.7
- 3Based on the landmark ADAG study with 507 participants
- 4Non-diabetic eAG is typically under 126 mg/dL (A1c < 5.7%)
- 5eAG helps bridge lab results and daily glucose monitoring
- 6Don't expect exact match with meter readings — they measure different things
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References
- Nathan DM, et al. Translating the A1C assay into estimated average glucose values. Diabetes Care. 2008;31(8):1473-1478. PMID: 18540046
- American Diabetes Association. Standards of Medical Care in Diabetes—2024. Diabetes Care. 2024;47(Suppl 1):S1-S321.
- Selvin E. Are there clinical implications of racial differences in HbA1c? Diabetes Care. 2016;39(8):1462-1467. PMID: 27457633
- Rohlfing CL, et al. Defining the relationship between plasma glucose and HbA(1c). Diabetes Care. 2002;25(2):275-278. PMID: 11815495
This article is for educational purposes only. eAG is an estimate and may not perfectly reflect individual glucose patterns. Always interpret results with your healthcare provider.