A glucose meter gives you one number for one moment. On its own that number is nearly meaningless — it is a still frame from a film. The value comes from the pattern that emerges when you collect enough of them.
The usual targets
For most non-pregnant adults with diabetes, the commonly cited targets are:
- Fasting or before a meal: 80–130 mg/dL (4.4–7.2 mmol/L)
- Two hours after the start of a meal: under 180 mg/dL (10.0 mmol/L)
- At bedtime: 100–140 mg/dL (5.6–7.8 mmol/L)
These are defaults, not rules. Older adults, people with a history of severe lows, people with significant other illnesses, and pregnant women all get different targets. Yours should come from your doctor, and Sukkari lets you set them in Settings.
Context is half the reading
170 mg/dL is a reasonable number ninety minutes after lunch and a poor one after twelve hours without food. This is why every reading in Sukkari asks for a context. Tagging honestly costs one tap and makes the difference between a log that shows patterns and a log that is just a column of numbers.
Time in range
Time in range — TIR — is the percentage of your readings that land between your target low and high. It has become the central metric of modern diabetes care because it captures something an average cannot: a person who swings between 50 and 300 and a person who sits steadily at 150 can post the identical average, but they are not in the same clinical situation at all.
The 2019 international consensus set these goals for most adults with type 1 or type 2:
- In range (70–180 mg/dL): above 70% of the time
- Below 70 mg/dL: under 4%
- Below 54 mg/dL: under 1%
- Above 180 mg/dL: under 25%
- Above 250 mg/dL: under 5%
Roughly speaking, each 10% improvement in time in range corresponds to about a 0.5% drop in A1c. Worth knowing when 70% feels far away: going from 40% to 50% is real, measurable progress.
Fix the lows first
If both time-below-range and time-above-range are off target, the lows get attention first. Highs damage over years; a severe low can cause harm within the hour. Any pattern of readings under 70 mg/dL deserves a conversation with your doctor about doses and timing before anything is done about the highs.
Variability
The coefficient of variation (CV) measures how much your readings scatter around their own average. At or below 36% is considered stable. Above that, the same average is being produced by bigger swings — and swings are what produce both the lows and the post-meal spikes. High variability usually traces back to inconsistent meal timing, inconsistent dose timing, or a mismatch between when insulin peaks and when food is absorbed.
How often to test
It depends entirely on your treatment. Someone on insulin may test four or more times a day; someone managing type 2 on metformin alone may be advised to test far less often. What is universally more useful than testing frequently is testing in a varied pattern — rotating between fasting, before meals, two hours after meals, and occasionally overnight. Ten readings spread across different moments say far more than thirty taken every morning at the same time.
A practical starting rhythm if nobody has given you one: fasting every morning, plus one paired reading each day — before a meal and two hours after the same meal, rotating which meal you pick. In a week you will have covered every meal, and the pattern will be obvious.