Glucose Ketone Index (GKI) Calculator
Enter your blood glucose and blood ketone readings to calculate your GKI. The calculator automatically converts glucose from mg/dL to mmol/L when needed.
- > 9.0 — Not in ketosis
- 6.0 – 9.0 — Low ketosis
- 3.0 – 6.0 — Moderate ketosis
- 1.0 – 3.0 — High ketosis
- < 1.0 — Very high therapeutic ketosis
What Is the GKI?
GKI stands for Glucose Ketone Index. It combines two biomarkers—blood glucose and blood ketones—into one number. Instead of looking at glucose or ketones separately, GKI gives you a clearer snapshot of your metabolic state, especially if you're tracking ketosis for performance, weight management, metabolic health, or therapeutic nutrition.
In simple terms, lower GKI values generally indicate deeper ketosis. Higher values suggest your body is relying more on glucose than ketones.
How the Formula Works
The GKI formula is straightforward:
GKI = Glucose (mmol/L) ÷ Ketones (mmol/L)
If your glucose meter displays mg/dL, you must first convert to mmol/L by dividing by 18. This calculator does that automatically when you select mg/dL.
Example Calculation
- Glucose: 90 mg/dL
- Ketones: 1.5 mmol/L
- Converted glucose: 90 ÷ 18 = 5.0 mmol/L
- GKI: 5.0 ÷ 1.5 = 3.33
A GKI of 3.33 would typically fall into a moderate-to-high ketosis range depending on your framework.
How to Take Better Readings
For more consistent results, keep your testing method consistent:
- Measure at the same time of day (many prefer morning, fasted).
- Stay hydrated before testing.
- Avoid testing right after intense exercise or a meal if your goal is trend consistency.
- Use blood ketone readings rather than breath or urine for GKI calculations.
- Track trends over days and weeks instead of reacting to one single value.
Interpreting Your GKI Range
GKI > 9.0
Usually indicates little to no nutritional ketosis. This is common after high-carbohydrate meals or in people not following a ketogenic approach.
GKI 6.0–9.0
Mild ketosis may be present, but ketone utilization is still relatively low. Often seen during transition phases.
GKI 3.0–6.0
Moderate ketosis. Many people targeting fat adaptation or general metabolic flexibility spend time here.
GKI 1.0–3.0
Higher ketosis. Common among people following stricter carbohydrate limits, fasting strategies, or advanced ketogenic protocols.
GKI < 1.0
Very deep ketosis. This range is often discussed in clinical or therapeutic contexts and should be approached thoughtfully.
What Can Affect GKI Day to Day?
- Carbohydrate intake: More carbs usually raise glucose and GKI.
- Protein amount and timing: Large protein loads may affect glucose in some individuals.
- Sleep quality: Poor sleep can raise glucose and reduce ketone production.
- Stress hormones: Cortisol and adrenaline can push glucose up.
- Exercise timing: Training can temporarily alter both glucose and ketones.
- Illness/inflammation: Can significantly change readings.
Practical Tips to Improve GKI (If Appropriate for You)
- Build meals around whole foods and non-starchy vegetables.
- Control added sugars and refined starches.
- Prioritize sleep and stress management.
- Use walking and resistance training consistently.
- Experiment with meal timing only if it fits your health status and schedule.
- Track both subjective markers (energy, focus, hunger) and objective markers (GKI trend).
Important Context and Safety Notes
GKI is a helpful metric, but it is not a diagnosis. It should be interpreted alongside your symptoms, medical history, goals, and professional guidance.
If you have diabetes, use glucose-lowering medication, are pregnant, or have any medical condition, consult your clinician before making diet or fasting changes. Seek urgent care for signs of diabetic ketoacidosis (DKA), which is not the same as nutritional ketosis.
Bottom Line
The GKI calculator is a simple but powerful way to quantify your metabolic state. Use it as a trend tool—not a perfection score. Over time, consistent tracking can reveal how food, sleep, stress, and activity affect your physiology, helping you make smarter decisions based on your own data.