GKI Calculator (Glucose Ketone Index)
Calculate your glucose ketone index (GKI) from blood glucose and blood ketones — a single number that tracks the depth of nutritional ketosis for keto and metabolic goals.
Beta-hydroxybutyrate from a blood ketone meter.
How to Use This Calculator
- Choose your glucose units — mg/dL or mmol/L.
- Enter your blood glucose and your blood ketones (BHB) from a blood ketone meter.
- Calculate to see your GKI and its ketosis zone. Lower values mean deeper ketosis.
Use blood (BHB) ketones for a valid GKI — urine and breath ketones don't work in this formula. The GKI tracks nutritional ketosis only, not diabetic ketoacidosis.
How the GKI Is Calculated
The glucose ketone index combines blood glucose and blood ketones into one ratio, giving a more complete picture of metabolic state than either alone. Glucose is converted to mmol/L first, then divided by ketones:
Example: glucose 90 mg/dL (5.0 mmol/L) and ketones 1.5 mmol/L → 5.0 ÷ 1.5 = GKI ≈ 3.3.
GKI Interpretation Zones
| GKI | Level of ketosis | Typical use |
|---|---|---|
| < 1 | Highest | Intensive therapeutic protocols (clinician-led) |
| 1–3 | High | Therapeutic ketosis |
| 3–6 | Moderate | Weight loss, metabolic health |
| 6–9 | Low | Light nutritional ketosis |
| > 9 | Minimal | Not in meaningful ketosis |
Use a blood ketone meter (BHB) for accuracy; breath and urine ketones don't give a valid GKI.
Who Uses the GKI & Measuring Ketones
Who tracks the GKI
The GKI was developed to monitor therapeutic ketosis, and it's used in research and clinical settings for ketogenic diets in epilepsy and as an adjunct in some metabolic and neurological protocols, as well as by people pursuing weight loss, metabolic health or athletic performance. Deeper (lower-GKI) targets are reserved for clinician-led therapeutic use.
Measuring blood ketones accurately
Three methods exist, and only one suits the GKI: a blood ketone meter measures beta-hydroxybutyrate (BHB) and is the most accurate for nutritional ketosis. Urine strips detect acetoacetate and become unreliable as your body adapts and spills fewer ketones into urine. Breath meters measure acetone and correlate loosely but are reusable and cheap over time. For a valid GKI, always use blood BHB.
Frequently Asked Questions
What is a good GKI?
It depends on your goal. A GKI of 3–6 suits general weight loss and metabolic health, 1–3 reflects deeper therapeutic ketosis, and under 1 is reserved for intensive clinician-led protocols. Lower means more ketosis.
How do you calculate the glucose ketone index?
Divide blood glucose in mmol/L by blood ketones in mmol/L. If your glucose is in mg/dL, divide it by 18.016 first. For example, 90 mg/dL (5.0 mmol/L) ÷ 1.5 mmol/L gives a GKI of about 3.3.
Can the GKI detect ketoacidosis?
No. The GKI tracks beneficial nutritional ketosis, not the dangerous, high-glucose, high-ketone state of diabetic ketoacidosis. If you have diabetes with high glucose and ketones, seek urgent care — use our DKA assessment.
When should I measure for the GKI?
For consistency, measure at the same time each day — many people test a few hours after waking and before eating. Use a blood glucose and blood ketone meter from the same sample window.
Blood, urine or breath ketones — which is best?
Blood ketone meters measure beta-hydroxybutyrate (BHB) and are the most accurate — and the only valid input for the GKI. Urine strips measure acetoacetate and become unreliable as the body adapts to ketosis. Breath analyzers measure acetone, correlate loosely, but are reusable and inexpensive over time.
Is a high GKI bad?
Not on its own. A high GKI simply means little or no ketosis, which is perfectly normal if ketosis isn't your goal. It only matters relative to what you're trying to achieve. Note that this is different from high glucose with high ketones in diabetes, which can signal ketoacidosis and needs urgent care.
Sources
- Meidenbauer JJ, Mukherjee P, Seyfried TN. The glucose ketone index calculator. Nutrition & Metabolism. 2015.
- Guidance on blood ketone (BHB) monitoring for nutritional ketosis.
Last reviewed: June 2025