What Is a Normal Time in Range Without Diabetes
People without diabetes spend most of the day between 70 and 140 mg/dL, about three hours above 140 (Shah et al. 2019; Spartano et al. 2024). The 70-180 mg/dL band is a diabetes target, not a normal range.
Adults without diabetes spend most of the day between 70 and 140 mg/dL. In a healthy cohort, the median time in that band was about 96% (Shah et al. 2019); a larger community cohort averaged roughly three hours a day above 140 mg/dL (Spartano et al. 2024). The 70-180 mg/dL time-in-range figure you see in CGM apps is a diabetes management target, not a definition of normal.
What is a normal time in range for someone without diabetes?
Time in range means the percentage of sensor readings that fall between two glucose thresholds. Most apps default to 70-180 mg/dL (3.9-10.0 mmol/L) because an international consensus set that range for people with diabetes, with a goal of more than 70% time in range (Battelino et al. 2019). That target exists because people with diabetes are balancing medication, especially insulin, against the risk of hypoglycemia.
The normal picture without diabetes is tighter. One multicentre study of healthy adults without diabetes found a median of about 96% of time between 70 and 140 mg/dL (3.9-7.8 mmol/L) (Shah et al. 2019). The larger Framingham Heart Study community sample found adults averaged about three hours a day above 140 mg/dL (Spartano et al. 2024). That is roughly 12% of the day. Post-meal rises can contribute, but the amount varies.
Time in 70-180 mg/dL can be high in people without diabetes because the band is wide, but it is not a pass mark. Sensors and people differ. The more useful number is time above 140 mg/dL, which was about three hours a day in one community sample (Spartano et al. 2024).
Why 70-180 mg/dL is a diabetes guideline, not normal
The 70-180 mg/dL band was chosen as a consensus target for people with diabetes (Battelino et al. 2019). The lower end protects against hypoglycemia when using insulin or some oral drugs. It was never meant to describe the glucose pattern of someone without diabetes.
For a person without diabetes, glucose is usually lower than this. Time above 140 mg/dL can happen after meals, but the amount varies. Time below 70 mg/dL can occur in some people, but the amount varies. The 70-140 mg/dL and above-140 mg/dL findings are study context, not diagnostic thresholds or pass/fail targets. CGM is wellness-only and does not diagnose diabetes.
- 70-180 mg/dL: a diabetes consensus range, with more than 70% time in range as the goal.
- 70-140 mg/dL: the band that captures most of the day in adults without diabetes.
- Above 140 mg/dL: not a diagnosis on its own, but the number worth watching if you want to see how much of your day is spent elevated.
What the curve looks like on a real CGM
A nondiabetic day is not a flat line. Meals push glucose up, but the size and timing of the rise vary. The rise happens because glucose from food enters the bloodstream faster than insulin can move it into muscle and fat, especially after a large or carbohydrate-heavy meal. A person without diabetes still has a functioning insulin response, so the rise is limited and short-lived.
Illustrative example only. Post-meal glucose can rise above 140 mg/dL and then return toward baseline, but timing and size vary.
Overnight can be the flattest part of the day in many people, but individual patterns vary. The time above 140 mg/dL can be scattered across meals, but the amount varies.
The common mistake is to chase a flat CGM line. Even in people without diabetes, a meal can produce a reading above 140 mg/dL. The point is how long it stays there and how fast it returns.
Your own time-in-range numbers
If you are looking at your own sensor export, start with these numbers. These are study observations, not diagnostic thresholds or pass/fail targets.
- Time above 140 mg/dL: about three hours a day is typical in a community sample (Spartano et al. 2024). A little less or more can be normal.
- Time below 70 mg/dL: low readings can occur in some people, but the amount varies. Unexplained lows or symptoms should be checked with a finger-prick meter and a clinician.
- Time between 70 and 140 mg/dL: in healthy adults, a median around 96% (Shah et al. 2019). Community samples show individual variation, so do not treat that as a pass mark.
- Time in 70-180 mg/dL: can be high because the band is wide, so it does not tell you much about normal physiology.
| Window | Who it is for | Typical finding |
|---|---|---|
| 70-180 mg/dL | Diabetes consensus target | >70% time is the goal (Battelino et al. 2019) |
| 70-140 mg/dL | Adults without diabetes | ~96% median in healthy adults (Shah et al. 2019) |
Scroll the table sideways for the rest →
Study observations. The first is a diabetes consensus target. The second is closer to the pattern seen in people without diabetes, not a diagnostic threshold or pass/fail target.
Two weeks of data beats a single day
Start by separating the diabetes target from the normal physiology window. If your app only shows 70-180 mg/dL time in range, do not optimize that number. Look for time above 140, the overnight baseline, and how long post-meal rises last. A brief rise that returns quickly is different from staying above 140 for most of the afternoon.
A single day is noisy. Sensor error, stress, poor sleep, exercise and what you ate the day before all move the line. Use at least two weeks of data before you draw conclusions about your pattern.
If you already have a CGM, you can upload a LibreView export file, Dexcom Clarity export file, Stelo export file, Lingo export file, or SiBionics export file to the free HealthOS CGM report. These are file uploads for the browser report, not live connections to the HealthOS app. The report calculates AGP, time in range, GMI, and biggest rises in the browser, no account. If you do not have a sensor, HealthOS Sensor is sold online at HealthOS Sensor. It is a wellness product, not a medical device. The HealthOS app is pre-launch; join the waitlist at https://healthosx.com/start.
Written by
HealthOS Research