Time in range

Time in range (also TIR): Time in range (TIR) is the percentage of glucose readings — typically from a continuous glucose monitor (CGM) — that fall within a target range, usually 70–180 mg/dL for most non-pregnant adults with diabetes.

Targets

The international consensus on TIR (Battelino et al., 2019) recommends >70% TIR for most adults with Type 1 or Type 2 diabetes, with less than 4% time below 70 mg/dL and less than 1% below 54 mg/dL.

Why TIR is informative beyond A1C

A1C is an average — it can hide wild swings between very high and very low. TIR captures variability. Two people can have the same 7.0% A1C with very different TIR profiles, and the one with more variability is at higher complication risk.

Improving TIR

The biggest levers are accurate carb counting (so insulin doses are right), pre-meal bolus timing (typically 10–20 minutes before eating), and treating the food types that cause repeated post-meal spikes.