Welcome to the Hgb to A1C calculator! This simple yet powerful tool helps you convert hemoglobin (Hgb) values into an estimated A1C percentage, which is commonly used to monitor blood sugar control over time. By entering your Hgb level, you can quickly determine your approximate A1C and even estimate your average glucose levels.
Whether you want to use the calculator right away or first understand how the formula works, you’ll find everything you need below — from the equations to an example calculation and explanations of each parameter.
Understanding the Formula
The Hgb to A1C calculator is based on straightforward mathematical relationships:
Hgb to A1C Formula:
A1C (%) = (Hgb in g/dL × 0.0915) + 2.15
A1C to Estimated Average Glucose (eAG) Formulas:
eAG (mg/dL) = (28.7 × A1C) − 46.7
eAG (mmol/L) = [(28.7 × A1C) − 46.7] ÷ 18.015
What does this mean? In simple terms:
- Your hemoglobin value is multiplied by a constant (0.0915).
- A baseline factor (2.15) is added to give an approximate A1C percentage.
- From the A1C, you can also predict your average blood sugar levels in either mg/dL or mmol/L, making the results practical for everyday diabetes monitoring.
Parameters Explained
Hgb (Hemoglobin in g/dL):
This is the concentration of hemoglobin in your blood. It’s typically measured during a routine blood test. Hemoglobin carries oxygen but also reflects glucose attachment, making it useful for estimating long-term sugar control.
A1C (%):
A measure of how much glucose is bound to hemoglobin. It represents your average blood sugar levels over roughly three months.
eAG (Estimated Average Glucose):
A conversion of A1C into actual blood sugar numbers, shown in either mg/dL or mmol/L. This makes the result more relatable if you monitor your blood sugar daily.
How to Use the Hgb to A1C Calculator — Step-by-Step Example
Let’s go through an example to see how the calculator works.
- Suppose your hemoglobin (Hgb) is 15 g/dL.
- Use the formula:
A1C = (15 × 0.0915) + 2.15
A1C = 1.3725 + 2.15 = 3.52% - Now convert A1C into eAG (mg/dL):
eAG = (28.7 × 3.52) − 46.7
eAG = 101.02 − 46.7 = 54.32 mg/dL - Convert to mmol/L:
eAG = 54.32 ÷ 18.015 = 3.01 mmol/L
So, a hemoglobin level of 15 g/dL corresponds to an A1C of 3.52%, with an estimated average glucose of 54.32 mg/dL (or 3.01 mmol/L).
Additional Information
Here’s a quick reference table linking A1C values with estimated glucose levels:
| A1C (%) | eAG (mg/dL) | eAG (mmol/L) |
|---|---|---|
| 5 | 97 | 5.4 |
| 6 | 126 | 7.0 |
| 7 | 154 | 8.6 |
| 8 | 183 | 10.2 |
| 9 | 212 | 11.8 |
FAQs
Hemoglobin (Hgb) is the protein in red blood cells that carries oxygen. A1C measures how much sugar has attached to hemoglobin, providing an average of blood sugar control.
No. The Hgb to A1C calculator offers an estimate for educational purposes only. For accurate results, a laboratory A1C test is recommended.
Many people monitor their glucose daily in mg/dL or mmol/L. The eAG value translates A1C percentages into numbers you’re familiar with, making it easier to understand long-term control.