ganak.appA1C Calculator
Convert A1C ↔ average glucose (eAG), estimate A1C from glucose readings, GMI, and fructosamine. Includes mg/dL ↔ mmol/L conversion, charts, and A1C range interpretation.
Convert HbA1c (%) to estimated average glucose (eAG). Typical lab values range from 4% to 14%.
Estimated Average Glucose (eAG) — 131 mg/dL (7.3 mmol/L)
A1C to Average Glucose
See how A1C maps to estimated average glucose in mg/dL and mmol/L.
A1C Conversion Table
Quick reference values for A1C and estimated average glucose.
| A1C (%) | eAG (mg/dL) | eAG (mmol/L) |
|---|---|---|
| 4.0 | 68 | 3.8 |
| 4.5 | 82 | 4.6 |
| 5.0 | 97 | 5.4 |
| 5.5 | 111 | 6.2 |
| 6.0 | 125 | 7.0 |
| 6.5 | 140 | 7.8 |
| 7.0 | 154 | 8.6 |
| 7.5 | 169 | 9.4 |
| 8.0 | 183 | 10.2 |
| 8.5 | 197 | 11.0 |
| 9.0 | 212 | 11.8 |
| 9.5 | 226 | 12.6 |
| 10.0 | 240 | 13.4 |
| 10.5 | 255 | 14.1 |
| 11.0 | 269 | 14.9 |
| 11.5 | 283 | 15.7 |
| 12.0 | 298 | 16.5 |
| 12.5 | 312 | 17.3 |
| 13.0 | 326 | 18.1 |
| 13.5 | 341 | 18.9 |
| 14.0 | 355 | 19.7 |
Informational only. These results are estimates. Lab A1C and clinical context may differ. Always consult your healthcare provider for diagnosis or treatment decisions.
What is A1C (HbA1c)?
Understanding the test for long-term glucose monitoring
A1C (also called HbA1c) reflects the percentage of glucose attached to hemoglobin in red blood cells. It represents your average blood sugar over roughly the past 2-3 months, which makes it useful for long-term glucose monitoring and diabetes screening.
This A1C calculator converts between A1C and estimated average glucose (eAG), so you can compare lab A1C results with daily blood glucose readings or CGM summaries. It doubles as a blood sugar to A1C calculator and an A1C to glucose calculator.
A1C to Average Glucose Formula
ADA eAG conversion between A1C and average glucose
The ADA eAG conversion uses a linear formula to translate A1C into estimated average glucose. You can also reverse it to calculate A1C from average glucose.
If you want to calculate A1C at home, average your glucose readings first, then apply the conversion below.
To convert glucose units: mmol/L = mg/dL / 18.
A1C Ranges (Diagnosis & Screening)
Normal, prediabetes, and diabetes thresholds for screening
A1C ranges are commonly used to screen for diabetes and prediabetes. Always consult a healthcare provider for diagnosis and treatment decisions.
| Category | A1C Range |
|---|---|
| Normal | Below 5.7% |
| Prediabetes | 5.7% - 6.4% |
| Diabetes | 6.5% and above |
GMI vs A1C (CGM Summary)
How CGM-derived GMI relates to lab A1C results
GMI (Glycemic Management Indicator) estimates A1C from CGM mean glucose. It can differ from lab A1C due to individual factors, lab methods, or differences between CGM averages and long-term hemoglobin glycation.
Use this calculator to compare GMI with A1C and to estimate average glucose from GMI.
Fructosamine to A1C
Shorter-term glycemic marker used when A1C is unreliable
Fructosamine reflects average glucose over roughly 2-3 weeks and can be helpful when A1C is unreliable (for example, with certain hemoglobin variants or recent changes in glucose control).
The conversion is an estimate-always interpret results with a clinician.
Frequently Asked Questions
Common questions about A1C levels, blood sugar, and diabetes management