Glucose Ketone Index (GKI) Calculator
Monitor your metabolic health and ketosis depth
What is the Glucose Ketone Index (GKI)?
The Glucose Ketone Index (GKI) is a single value that represents the relationship between your blood sugar and ketone levels. Developed by Dr. Thomas Seyfried and his team, it provides a more accurate picture of your metabolic state than looking at glucose or ketones individually.
While blood ketone levels alone can tell you if you are in ketosis, the GKI factor accounts for the presence of glucose, which can inhibit the metabolic benefits of ketones even if they are elevated.
How is GKI Calculated?
To calculate your GKI, you need to have both your blood glucose and blood ketone measurements taken at the same time (ideally in a fasted state). The formula is:
GKI = [Glucose ÷ 18.016] / Ketones (if glucose is in mg/dL)
GKI = Glucose / Ketones (if glucose is in mmol/L)
Understanding Your Results
| GKI Range | Metabolic State |
|---|---|
| Under 1.0 | Highest Therapeutic Ketosis (Clinical use) |
| 1.0 – 3.0 | High Therapeutic Level (Deep Ketosis) |
| 3.0 – 6.0 | Moderate Ketosis (Weight loss & Health) |
| 6.0 – 9.0 | Low Ketosis (Nutritional Ketosis) |
| Over 9.0 | No Ketosis |
Why Monitor GKI?
The GKI is particularly useful for individuals using the ketogenic diet for therapeutic purposes, such as managing Type 2 Diabetes, inflammatory conditions, or metabolic health. A lower GKI indicates higher metabolic efficiency and deeper fat-burning states.
Real-World Example
If your blood glucose is 80 mg/dL and your ketones are 2.0 mmol/L:
- Convert glucose to mmol/L: 80 / 18.016 = 4.44
- Divide by ketones: 4.44 / 2.0 = 2.22 GKI
In this example, a GKI of 2.22 signifies a High Therapeutic Level of ketosis.