Free tool
GRI calculator
Glycemia Risk Index from your CGM report. Runs in your browser; nothing is sent anywhere.
Take the four out-of-range percentages from any CGM report (Dexcom Clarity, LibreView, Glooko, or the app) and enter them below. The result is the GRI score with its zone letter, the way Glide shows it in the app.
What GRI is
The Glycemia Risk Index is a single 0–100 score for a CGM trace, published by Klonoff and colleagues in 2023. Lower is better. It was built to match how 330 clinicians ranked 225 real 14-day CGM traces, and it weights lows more heavily than highs, because that is how the clinicians ranked them. Time in range alone treats a day with a bad low the same as a day that ran high; GRI does not.
The formula
GRI = 3.0 × very low + 2.4 × low + 1.6 × very high + 0.8 × high, capped at 100. Each term is a percentage of time.
The same number in two parts: a hypoglycemia component (very low + 0.8 × low) and a hyperglycemia component (very high + 0.5 × high). GRI = 3.0 × hypo + 1.6 × hyper. The calculator prints both.
The zones
A GRI number alone is ambiguous, so the paper splits the scale into five zones
and Glide always shows the letter next to the number, as in 23·A.
| Zone | GRI | Reads as |
|---|---|---|
| A | 0–20 | Lowest risk |
| B | 21–40 | Low |
| C | 41–60 | Moderate |
| D | 61–80 | High |
| E | 81–100 | Highest risk |
Zone boundaries follow the paper. Glide rounds the score to a whole number first and zones the rounded value, so the letter always agrees with the number on screen.
Where to find the four numbers
- Dexcom Clarity: Overview → the time-in-range bar. Hover or tap the two red and two orange bands.
- LibreView: Glucose Reports → Snapshot, the same five-band bar.
- Glide: Home shows today's GRI with its zone; the Insights tab shows the 14-day figure with the formula filled in.
The international consensus on CGM metrics (Battelino et al., 2019) recommends at least 14 days of data with the sensor worn 70% of the time before reading these percentages as a summary.