1. What is A1C?

A1C (glycated hemoglobin) is a blood test that measures your average blood glucose levels over the past 2-3 months. It's expressed as a percentage and is a key indicator of long-term glucose control.

2. How Does the Calculator Work?

The calculator uses the ADAG formula to estimate A1C from average glucose:

Where:

• \( eAG \) — Estimated Average Glucose (mg/dL)
• 46.7 and 28.7 — Conversion factors from the ADAG study

Explanation: This formula provides a linear relationship between average glucose levels and A1C percentage.

3. Importance of A1C Measurement

Details: A1C is crucial for diabetes diagnosis and management. It reflects long-term glucose control and correlates with diabetes complications risk.

4. Using the Calculator

Tips: Enter your average glucose level in mg/dL. The value must be positive. For best results, use glucose data from continuous monitoring or frequent fingerstick tests.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal A1C level?
A: Below 5.7% is normal, 5.7%-6.4% indicates prediabetes, and 6.5% or higher suggests diabetes.

Q2: How often should A1C be checked?
A: Every 3 months if not at target or therapy changed, every 6 months if stable and at target.

Q3: Can A1C be inaccurate?
A: Yes, conditions affecting hemoglobin (anemia, hemoglobinopathies) or red cell turnover can affect A1C accuracy.

Q4: What's the difference between A1C and eAG?
A: A1C is a percentage reflecting long-term control, while eAG is in mg/dL and represents an estimated average glucose level.

Q5: Why are there different conversion formulas?
A: Different studies produced slightly different correlations between A1C and glucose levels. This calculator uses the widely accepted ADAG formula.