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GKI Calculator
Your Glucose Ketone Index from one paired reading — the same formula and zone boundaries the metabomap app computes on every reading you log.
Your glucose ketone index
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Enter both readings to see your GKI and zone.
- Deep ketosis
- GKI below 1
- Therapeutic ketosis
- GKI 1 – 2.9
- Moderate ketosis
- GKI 3 – 5.9
- Low ketosis
- GKI 6 – 8.9
- Not in ketosis
- GKI 9 or higher
Formula: (glucose in mg/dL ÷ 18.016) ÷ ketones in mmol/L, rounded to one decimal — the same math and the same zone boundaries the metabomap app uses for every paired reading.
The formula, worked
GKI = (glucose mg/dL ÷ 18.016) ÷ ketones mmol/L
glucose 85 mg/dL, ketones 1.6 mmol/L:
= (85 ÷ 18.016) ÷ 1.6
= 4.72 ÷ 1.6
= 2.9 → therapeutic ketosis
The division by 18.016 converts glucose from mg/dL (US meters) to mmol/L, so both readings are in the same unit before you divide. Meters that already read in mmol/L divide directly.
GKI zones
| Zone | GKI | What it reflects |
|---|---|---|
| Deep ketosis | below 1 | The deepest band — usually only seen with extended fasting or very strict, often clinically supervised protocols. |
| Therapeutic ketosis | 1 – 2.9 | Deep nutritional ketosis; where dedicated keto practitioners often aim to sit. |
| Moderate ketosis | 3 – 5.9 | Solid nutritional ketosis — a common everyday range for consistent low-carb eating. |
| Low ketosis | 6 – 8.9 | The edge of ketosis; typical when carbs are creeping or you are early in adaptation. |
| Not in ketosis | 9 or higher | Glucose is dominant; ketone production is minimal. |
Zones describe metabolic state for tracking purposes — they are not medical targets, and this page isn’t medical advice. If you take medication that affects glucose or ketones, work with your clinician.
GKI questions, answered
What is GKI?
The Glucose Ketone Index is the ratio of your blood glucose to your blood ketones, both expressed in mmol/L. A high ketone reading alone doesn’t tell the whole story — the same ketone level means something different at a glucose of 75 than at 110. GKI puts both on one scale, which is why many in the keto community regard it as the single most useful number for tracking depth of ketosis.
How is GKI calculated?
GKI = (glucose ÷ 18.016) ÷ ketones, where glucose is in mg/dL and ketones are in mmol/L. The 18.016 converts US-style glucose readings (mg/dL) into mmol/L so both sides of the ratio speak the same unit. If your meter already reads glucose in mmol/L, skip the division and just divide glucose by ketones. Example: glucose 85 mg/dL and ketones 1.6 mmol/L → (85 ÷ 18.016) ÷ 1.6 = 2.9.
What do the GKI zones mean?
Community convention groups GKI into five bands. Below 1: the deepest band, typically seen during extended fasting. 1 to just under 3: deep nutritional ketosis. 3 to just under 6: moderate nutritional ketosis, where many people doing keto for everyday wellness goals sit. 6 to just under 9: light nutritional ketosis. 9 and above: outside ketosis. These are descriptive bands for understanding your own readings, not medical targets — what matters is watching where your number sits and how your food and fasting move it.
When should I measure for GKI?
Consistency beats timing. Pick one or two fixed points — commonly waking (fasted) and pre-dinner — and measure at the same times daily. Both readings should come from the same sitting, since GKI is a ratio: a morning glucose paired with an evening ketone reading produces a meaningless number.
Do I need a blood ketone meter, or do urine strips work?
GKI needs blood ketones in mmol/L, so you’ll want a meter that reads both glucose and ketones — most ketone meters do, and you just type the readings in. Urine strips measure a different thing — spillover, not blood concentration — and they fade as your body adapts, so they can’t feed this formula. Breath meters use their own units and don’t slot in either.
Does metabomap calculate GKI automatically?
Yes. Log a glucose and ketone reading as a pair and metabomap computes your GKI on the spot, plots it on charts, and shows which zone band you’re in — right next to the meals you logged that day, so you can see what moved it. Glucose, ketone, and GKI tracking are all in the free tier.
Stop calculating this by hand.
metabomap computes your GKI on every paired reading, charts it over time in its zone bands, and sits right next to your food log — so you can see what moved it. Free.
Track GKI automatically