Time in Range: What It Is and What Targets Mean

Time in Range (TIR) is the percentage of the day your glucose stays inside a target band — most often 70–180 mg/dL (3.9–10.0 mmol/L). International consensus guidelines suggest many adults with type 1 or type 2 diabetes aim for more than 70% of readings in range, but targets are individual, and your care team sets the number that is right for you.

Unlike a single reading or a lab average, TIR tells you how much of your day is spent near target versus running high or low. It has become one of the most useful ways to summarize day-to-day glucose control.

What Time in Range Actually Measures

TIR is built from many glucose values over a period — usually collected by a continuous glucose monitor (CGM) or from frequent fingerstick readings. Each value is sorted into a zone, and TIR is the share that lands inside your target band. Two related numbers usually travel with it: Time Below Range (TBR) and Time Above Range (TAR). A high TIR is only meaningful when TBR stays low — spending less time high should never come at the cost of dangerous lows.

Think of a single fingerstick as one photograph and TIR as a time-lapse of the whole day. A reading of 130 mg/dL (7.2 mmol/L) at breakfast tells you where you were at that moment; TIR tells you whether that moment was typical or an exception. Reported over a set window — often the last 14 days, provided the data covers most of each day — TIR turns dozens or hundreds of scattered numbers into one figure you can watch move over time.

It is worth knowing where the 70–180 mg/dL (3.9–10.0 mmol/L) band comes from. The lower bound sits just above the level where hypoglycemia symptoms typically begin, and the upper bound reflects a widely used post-meal ceiling. That is why TIR is reported alongside how much time is spent below and above the band: the goal is not simply a high percentage in range, but a healthy distribution with very little time low.

International Time in Range Targets

An international consensus group (published in Diabetes Care) proposed standard targets for many non-pregnant adults with type 1 or type 2 diabetes. These are general reference goals, not personal prescriptions — individual targets vary, and your care team sets yours.

As a rough guide, each additional 5% of Time in Range is often described as clinically meaningful. Older adults or people at higher risk of hypoglycemia are frequently given a wider, safer target (for example, more than 50% in range with even tighter limits on lows) — again, this is a conversation for you and your doctor. If you ever see a very low reading or have symptoms of severe hypoglycemia, treat it right away and seek urgent medical help.

Time in Range vs A1C (HbA1c)

A1C estimates your average glucose over the past two to three months and is measured with a lab blood test. It is valuable, but an average hides the story: two people can share an identical A1C while one stays steady near target and the other swings between highs and lows that cancel out on paper. Time in Range exposes that difference because it counts how the day is actually spent, not just the midpoint.

The two measures work together rather than compete. A1C remains a standard benchmark your clinician relies on, while TIR adds texture — showing variability, the timing of highs, and how often lows occur. If you want to understand how averages translate into an estimated A1C, see our A1C to average blood sugar chart and the note on how an estimated A1C is calculated and its limits.

It also helps to remember that the standard 70% target is not one-size-fits-all. Pregnancy, including gestational diabetes, uses tighter targets and a different band, so those readers should follow the goals their care team provides rather than the general adult figures above. The same caution applies to young children and anyone prone to frequent lows. Whatever your situation, the number that matters is the one set with your doctor — the consensus targets are a starting point for that conversation, not a substitute for it.

Why Time in Range Matters Day to Day

The appeal of TIR is that it maps onto how you actually feel. Long stretches above range often show up as fatigue or thirst, while time below range can bring shakiness or confusion — so a rising in-range percentage frequently tracks with steadier days. It also gives you feedback on a timescale you can act on: A1C shifts slowly over months, but you can see today's Time in Range respond to a change in a meal, a walk, or your daily routine. That faster feedback loop is what makes small, sustainable adjustments easier to notice. As with any change to how you manage diabetes, discuss what you observe with your doctor before adjusting anything about your care.

How to Improve and Track Your Time in Range

Because TIR depends on many data points, it is most reliable when you have consistent readings — whether from a CGM or from a regular fingerstick routine. Sparse or clustered readings (for example, only when you feel unwell) can skew the number, so a steady logging habit matters. Tagging each reading with context (fasting, before a meal, after a meal, bedtime) helps you and your clinician see why time is being spent out of range, such as recurring post-meal spikes or a morning rise. If you are unsure how often to test, our guide to how often to check your blood sugar can help — and your care team can tailor a schedule to you.

Seeing Your Time in Range in GlucoLog

GlucoLog does not measure your glucose — it is a logging and visualization tool, not a glucometer or CGM. When you record readings (in mg/dL or mmol/L) with meal-context tags, GlucoLog visualizes your Time in Range alongside 7-day to 1-year trend charts, so a pattern of highs or lows becomes easy to see at a glance. You can also export a PDF report — including your average, Time in Range, and reading history — to bring to an appointment. For a walkthrough of reading these charts, see our guide on blood sugar trends and charts.

Frequently Asked Questions

What is a good Time in Range percentage?

International consensus suggests many non-pregnant adults aim for more than 70% of the day within 70–180 mg/dL (3.9–10.0 mmol/L), while keeping time below 70 mg/dL under about 4%. These are general goals — your personal target depends on your situation and is set by your care team.

Is Time in Range better than A1C?

Neither replaces the other. A1C is a lab-measured average your doctor uses as a benchmark; Time in Range shows the day-to-day variability that an average can mask. Used together, they give a fuller picture of glucose patterns.

Do I need a CGM to know my Time in Range?

A CGM makes TIR far easier because it captures readings continuously, but you can approximate it from frequent, consistent fingerstick logs. The more readings you record, the more representative your Time in Range will be.