Time in Range (TIR): Targets, CGM Data, and Manual Logs

A1C summarizes a longer period. Time in range, or TIR, answers a different question: during the period measured, how often was glucose inside an agreed target range? It is most clinically meaningful when calculated from continuous glucose monitor data because a CGM samples throughout the day and night.

Put simply, time in range (TIR) is the percentage of measured time glucose stays in a target range. For many nonpregnant adults using CGM, the standard range is 70–180 mg/dL (3.9–10.0 mmol/L) and a common goal is more than 70%. Individual goals can be different.

New to A1C? Read our A1C guide. Curious about carb myths? See Carb Myths. Learn more about GluKee's approach to diabetes management.

What Exactly Is Time in Range?

Time in range measures the share of a monitored period that glucose values fall inside a defined target. Unlike A1C, which reflects a longer-term average, CGM-derived TIR preserves information about highs, lows, and daily timing.

Clinical TIR is typically measured using continuous glucose monitoring (CGM). An app can also show what percentage of manually logged or meter-imported spot readings fell inside a range, but that is a reading-based summary, not continuous time in range. Testing times influence it, so the two percentages should not be compared as if they were the same dataset.

The TIR Target Ranges: What Should You Aim For?

The standard target range for most people with diabetes is 70-180 mg/dL (3.9-10.0 mmol/L). This range balances the need to avoid hypoglycemia (dangerously low blood sugar) while keeping glucose levels from getting too high.

Current international consensus guidelines recommend these TIR targets:

• More than 70% TIR: Time spent between 70-180 mg/dL for many nonpregnant adults using CGM
• Less than 4% below range: Time spent below 70 mg/dL (hypoglycemia)
• Less than 25% above range: Time spent above 180 mg/dL (hyperglycemia)

These targets can be adjusted based on your individual circumstances, such as age, diabetes duration, and risk factors for complications.

Why TIR Matters More Than A1C Alone

The practical value of TIR is that it reveals variability hidden by an average. Two people can have similar A1C results but different daily patterns:

• Person A: Stable glucose levels throughout the day (high TIR)
• Person B: Frequent spikes and crashes that average out (low TIR)

TIR should be reviewed together with time below range, time above range, the glucose trace, and A1C. A high TIR percentage is not a reason to ignore repeated lows, and any treatment change should be discussed with a qualified clinician.

How to Track and Improve Your TIR

Improving your TIR requires understanding what affects your glucose levels and making targeted adjustments. Here's how to get started:

1. Get the Right Tools

Use a CGM if you and your care team need clinical time-in-range data. If you use a meter, treat app range percentages as summaries of the readings you chose to take, and keep timing reasonably consistent when comparing one period with another.

2. Track Everything That Matters

Use an app to correlate your glucose data with:

• Meals and carbohydrate intake
• Physical activity and exercise
• Medications and insulin dosing
• Stress levels and sleep quality
• Alcohol consumption and illness

3. Identify Your Patterns

Look for common TIR challenges:

• Morning highs: Dawn phenomenon or inadequate basal insulin
• Post-meal spikes: Carbohydrate timing or medication adjustments needed
• Overnight lows: Patterns can help you and your care team decide what to adjust
• Exercise-related changes: Blood sugar responses to different activities

4. Prepare Better Questions

Use your data to prepare a focused review with your care team:

• Meal timing and composition: Which repeated patterns deserve attention?
• Insulin or medication: Is the pattern clinically meaningful, and what is safe to change?
• Exercise: Does timing appear connected to highs or lows?
• Monitoring: Is your current testing schedule capturing enough information?

A Better Way to Review Progress

Compare similar periods and look for repeatable patterns rather than chasing a perfect daily score. Useful review questions include:

• Are lows becoming more or less frequent?
• Do the same meals or times of day repeatedly sit above range?
• Did a schedule, medication, illness, sleep, or activity change happen at the same time?

Bring the pattern and its context to your care team. Do not change insulin or medication from an app percentage alone.

TIR for Different Types of Diabetes

Type 1 Diabetes

For people with type 1, TIR is especially valuable because it helps optimize insulin dosing and timing. Many aim for 70% or higher TIR, with careful attention to hypoglycemia prevention.

Type 2 Diabetes

TIR helps people with type 2 understand how lifestyle factors affect glucose control. It can guide decisions about medication adjustments and help track the effectiveness of dietary changes.

Gestational Diabetes

During pregnancy, TIR targets may be adjusted to ensure fetal safety while avoiding maternal hypoglycemia. Continuous monitoring helps achieve optimal outcomes for both mother and baby.

How GluKee Handles Range Summaries

GluKee can organize manual readings, supported Bluetooth meter imports, and connected health data beside meals, medication, activity, weight, blood pressure, and notes. Its range summary describes the readings available to the app. It does not fill the gaps between finger-stick checks or recreate a continuous CGM trace.

Getting Started with TIR Tracking

Ready to start tracking your TIR? Here's your action plan:

1. Discuss with your healthcare provider - Get their guidance on TIR targets and monitoring options
2. Choose a CGM system - Select one that fits your lifestyle and insurance coverage
3. Get an app for tracking - Use tools that correlate TIR with your daily activities
4. Start logging everything - Track meals, exercise, medications, and how they affect your glucose
5. Review and adjust regularly - Use your data to make continuous improvements

Remember, TIR is a review tool, not a grade. Prioritize safety, especially time below range, and interpret changes with the care team that knows your treatment and health history.