Time above range (TAR)
Also called time high, time in hyperglycemia.
Time above range is the share of CGM values over 180 mg/dL (10.0 mmol/L). Level 1 is 181 to 250 mg/dL (10.1 to 13.9 mmol/L) and level 2 is over 250 mg/dL (13.9 mmol/L). It is where the spikes after meals and the nights that ran high show up. (International consensus on time in range, 2019)
Target
Under 25% of the time above 180 mg/dL (10.0 mmol/L) and under 5% above 250 mg/dL (13.9 mmol/L) for most adults. (ADA Standards of Care 2026, section 6)
Formula
TAR (%) = CGM values over 180 mg/dL ÷ all CGM values × 100
Worked example
Over 14 days, 806 of 4,032 values above 180 mg/dL is 20% TAR, about 4 hours 48 minutes a day. If 161 of those are above 250 mg/dL, the level 2 share is 4%.
Related terms
Sources, quoted
- International consensus on time in range, 2019: “Time above range (TAR): % of readings and time 181–250 mg/dL (10.1–13.9 mmol/L) Level 1”
- International consensus on time in range, 2019: “Time above range (TAR): % of readings and time >250 mg/dL (>13.9 mmol/L) Level 2”
- ADA Standards of Care 2026, section 6: “Percent of time in level 1 hyperglycemia <25% (most adults); <50% (older adults with complex/intermediate health)”
- ADA Standards of Care 2026, section 6: “Percent of time in level 2 hyperglycemia <5% (most adults); <10% (older adults with complex/intermediate health)”
Every quote above is checked against its source page before each update of this site; last checked 2026-10-06. The worked example is our own arithmetic. This page explains a term; it is not advice for a person's treatment.