GKI calculator: glucose ketone index.
GKI compares your blood glucose to your blood ketones in one number. Enter a reading from your meter or lab report below and it calculates instantly, right in your browser.
Enter both readings to see your GKI.
Calculated in your browser; nothing is sent or saved.
Why GKI needs a blood ketone reading
GKI only works with beta-hydroxybutyrate (BHB), the ketone body measured in blood. Urine strips measure a different ketone, acetoacetate, and many bodies excrete less of it as they adapt to ketosis; good for a quick in-ketosis check, not a precise level. Breath meters estimate acetone, which tracks ketosis loosely and compares best against the same device over time. Neither urine nor breath readings are interchangeable with blood BHB, so neither can stand in for GKI.
The formula
GKI = blood glucose (mmol/L) ÷ blood BHB (mmol/L). If your meter reports glucose in mg/dL, this calculator converts it to mmol/L by dividing by 18.016, the molecular-weight factor from the paper that introduced GKI (see Sources). Blood BHB meters already read in mmol/L, so that side needs no conversion.
What the number means
GKI was developed to monitor metabolic therapy in brain cancer care, not as a general wellness target. In that paper, the researchers describe the "zone of metabolic management" as "likely entered with GKI values between 1 and 2 for humans," with "optimal management… predicted for values approaching 1.0." That is a clinical target for a specific therapeutic context, set and tracked by a doctor, not a general health goal.
Keto-Mojo, a ketone meter maker, publishes a broader general-interest chart for its customers. It is that company's own guide, not medical guidance:
| GKI | What it means |
|---|---|
| ≤ 1 | Highest therapeutic level of ketosis |
| 1–3 | High therapeutic level of ketosis |
| 3–6 | Moderate level of ketosis |
| 6–9 | Low level of ketosis |
| ≥ 9 | Not in ketosis |
KetoCypher is a wellness and tracking tool, not a medical device. It does not diagnose or treat any condition, and nutrition and lab figures are representative estimates. If you're using GKI for a medical reason, such as metabolic therapy, work with a qualified professional instead of relying on this page.
Log it once, see the trend
KetoCypher lets you log your GKI straight from a combo meter or lab report, right alongside glucose and ketones, so you can watch the trend over weeks instead of redoing this math every time.
Sources
- Meidenbauer JJ, Mukherjee P, Seyfried TN. "The glucose ketone index calculator: a simple tool to monitor therapeutic efficacy for metabolic management of brain cancer." Nutrition & Metabolism. 2015;12:12. doi:10.1186/s12986-015-0009-2 (full text PDF). Source for the GKI formula, the 18.016 glucose conversion factor, and the zone-of-metabolic-management target range.
- Keto-Mojo. "What is GKI, Glucose Ketone Index?" and its GKI levels chart. Manufacturer guide, cited above only as that company's own interpretation, not medical guidance.