Time in Range is the percentage of your glucose readings that land between 70 and 180 mg/dL. The international consensus target for most adults with type 1 or type 2 diabetes is spending more than 70% of the day in that range — about 17 hours — while keeping time below 70 mg/dL under 4%. Different targets apply during pregnancy and for older or higher-risk adults, so your personal goal is worth confirming with your care team.
TIR exists because A1C hides the plot. Two people can share an identical A1C where one rides a smooth line and the other bounces between 55 and 300 all day. TIR is the metric that tells those stories apart, and it updates in real time instead of every three months.
Day to day, TIR is the number that actually reflects what you did this week — the meals that behaved, the ones that did not, the lows you caught early. Most people check it as a 7-day, 14-day, or 30-day view in their CGM app.
A few things worth knowing:
- Each 5% improvement in TIR is meaningful — that is over an hour more per day in range.
- Chasing 100% usually means trading spikes for lows; the consensus targets deliberately leave room.
- Range 70–180 is the standard, but what is realistic for you right now is individual — progress beats perfection.
