# What is my GKI ratio?

Works out the glucose ketone index (GKI): blood glucose divided by blood ketones (β-hydroxybutyrate), both in mmol/L, with glucose in mg/dL or mmol/L.

- Page: https://www.acalculator.org/health/gki-calculator
- JSON spec: https://www.acalculator.org/health/gki-calculator.json
- Version: e8c8d676ed38

## Default answer

Example with the default inputs (Glucose unit mg/dL, Blood glucose (mg/dL) 80, Blood ketones (mmol/L) 2): Glucose and ketones of these readings give a glucose ketone index of 2.2.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| unit | Glucose unit | The unit of your glucose meter: mg/dL (United States) or mmol/L. |
| glucose | Blood glucose (mg/dL) | Your blood glucose reading in mg/dL. |
| glucoseMmol | Blood glucose (mmol/L) | Your blood glucose reading in mmol/L. |
| ketones | Blood ketones (mmol/L) | Your blood β-hydroxybutyrate reading in mmol/L, from a blood ketone meter, taken at the same time. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| gki | Glucose ketone index | Glucose (mmol/L) ÷ ketones (mmol/L). |
| reading | Reading | Where the GKI falls in the paper’s description. |
| glucoseMmolL | Glucose (mmol/L) | The glucose in mmol/L: mg/dL ÷ 18.016. |

## Method

GKI = glucose (mmol/L) ÷ ketones (mmol/L) = glucose (mg/dL) ÷ (18.016 × ketones (mmol/L)).

## Assumptions

- Glucose and ketones are blood readings taken at the same time.
- Ketones are blood β-hydroxybutyrate in mmol/L (not urine or breath ketones).
- Glucose mg/dL ÷ 18.016 = mmol/L, the factor in the GKI paper.

## Worked examples

1. unit = mmol, glucoseMmol = 4.5, ketones = 4.5 gives gki = 1, reading = 1.0 or below: the paper’s target for brain tumor management. Source: Meidenbauer JJ, Mukherjee P, Seyfried TN, The glucose ketone index calculator: a simple tool to monitor therapeutic efficacy for metabolic management of brain cancer, Nutr Metab 2015;12:12 (GKI = glucose mmol/L ÷ ketone mmol/L; mg/dL ÷ 18.016), https://pmc.ncbi.nlm.nih.gov/articles/PMC4367849/ (retrieved 2026-10-05).
2. unit = mgdl, glucose = 80, ketones = 2 gives gki = 2.220249, glucoseMmolL = 4.440497. Source: Meidenbauer JJ, Mukherjee P, Seyfried TN, The glucose ketone index calculator: a simple tool to monitor therapeutic efficacy for metabolic management of brain cancer, Nutr Metab 2015;12:12 (GKI = glucose mmol/L ÷ ketone mmol/L; mg/dL ÷ 18.016), https://pmc.ncbi.nlm.nih.gov/articles/PMC4367849/ (retrieved 2026-10-05).
3. unit = mgdl, glucose = 95, ketones = 0.5 gives gki = 10.546181, reading = Above 2: above the paper’s zone of metabolic management. Source: Meidenbauer JJ, Mukherjee P, Seyfried TN, The glucose ketone index calculator: a simple tool to monitor therapeutic efficacy for metabolic management of brain cancer, Nutr Metab 2015;12:12 (GKI = glucose mmol/L ÷ ketone mmol/L; mg/dL ÷ 18.016), https://pmc.ncbi.nlm.nih.gov/articles/PMC4367849/ (retrieved 2026-10-05).

## FAQ

### What is the glucose ketone index?

The glucose ketone index (GKI) is your blood glucose divided by your blood ketones (β-hydroxybutyrate), both in mmol/L. It puts the two readings of ketosis into one number: the lower the GKI, the more ketones there are compared with glucose.

### How do I calculate GKI with glucose in mg/dL?

Divide the glucose by 18.016 to get mmol/L, then divide by the ketones in mmol/L. Glucose 80 mg/dL is 4.44 mmol/L; with ketones of 2.0 mmol/L the GKI is 4.44 ÷ 2 = 2.2.

### What is a good GKI?

There is no single target for everyone. The 2015 paper that described the GKI, written for brain cancer research, used a target of 1.0 and said the zone of metabolic management is likely entered between 1 and 2. Talk with your doctor before aiming for a number.

### When should I measure glucose and ketones?

Take both readings at the same time, from the same finger stick where your meters allow. The GKI paper suggests testing 2 to 3 hours after a meal, twice a day if possible.

### Can I use urine or breath ketones?

No. The GKI uses blood β-hydroxybutyrate in mmol/L from a blood ketone meter. Urine strips and breath meters measure other ketones in other units.

### Is the GKI safe to use with diabetes?

If you have diabetes, especially type 1, high ketones with high glucose can be a sign of ketoacidosis, which is an emergency. Do not use the GKI to manage diabetes without your care team.

## 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, retrieved 2026-10-05. https://pmc.ncbi.nlm.nih.gov/articles/PMC4367849/
- Centers for Disease Control and Prevention. Diabetic Ketoacidosis, retrieved 2026-10-05. https://www.cdc.gov/diabetes/about/diabetic-ketoacidosis.html