CGM · time in range
Time in range calculator.
Enter how many CGM readings (or minutes or hours) fell in each of five glucose ranges. The page gives each range as a percent, the time per day in range, and a check against the international consensus targets.
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How time in range works
Time in range (TIR) is the percentage of CGM readings, or time, between 70 and 180 mg/dL (3.9 to 10.0 mmol/L). The 2019 international consensus also tracks time below range (TBR, below 70 mg/dL, with a separate level below 54 mg/dL) and time above range (TAR, above 180 mg/dL, with a separate level above 250 mg/dL). The percentage for each band is its count divided by the total count.
Consensus targets. For adults with type 1 or type 2 diabetes: TIR above 70 percent (more than 16 h 48 min a day), time below 70 under 4 percent, below 54 under 1 percent, time above 180 under 25 percent and above 250 under 5 percent. For older or high-risk people: TIR above 50 percent, time below 70 under 1 percent and time above 250 under 10 percent. The consensus also says targets must be personalized, and that at least 70 percent of data from 14 days of wear is recommended.
Worked example. Out of 1,000 readings: 8 below 54, 32 at 54 to 69, 660 in range, 220 at 181 to 250 and 80 above 250. TIR is 660 ÷ 1000 = 66.0% (15 h 50 min a day), time below 70 is 4.0%, time above 180 is 30.0% and above 250 is 8.0%. Against the adult targets only the below-54 target is met (0.8% is under 1%); 66.0% is not above 70%, 4.0% is not below 4%, 30.0% is not below 25% and 8.0% is not below 5%.
Frequently asked questions
What is time in range?
The percentage of CGM readings or time between 70 and 180 mg/dL (3.9 to 10.0 mmol/L). If 660 of 1,000 readings fall in that range, time in range is 66 percent.
What is the consensus time in range target?
For adults with type 1 or type 2 diabetes the 2019 international consensus targets more than 70 percent of time in range, which is more than 16 hours 48 minutes a day. For older or high-risk people it is more than 50 percent.
How much time below range is acceptable?
The adult consensus targets are under 4 percent below 70 mg/dL and under 1 percent below 54 mg/dL. For older or high-risk people the target for below 70 mg/dL is under 1 percent.
Are these targets right for me?
They are a starting point. The consensus says CGM-based targets must be personalized, so ask your care team what yours should be.
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Educational worked example, not medical advice
This page shows arithmetic and published rules of thumb for learning. It is not a dosing instruction, a diagnosis or a treatment plan, and it does not know your insulin, your body or your health history. Never change insulin or medicine because of a number on this page. Confirm every setting and target with your diabetes care team. If you have symptoms of a very low or very high glucose, follow your care plan; in an emergency call your local emergency number.