Glucose log · averages
Glucose log averager.
Paste fasting readings in one box and any other readings, such as sick-day checks, in the other, one reading per line. The page returns the count, mean, median, lowest, highest, spread and number of readings below 70 mg/dL (3.9 mmol/L). Private: runs in your browser.
How the averager works
Each non-empty line in a box is one reading. The page takes the last number on the line (ignoring clock times and ISO dates), skips readings outside a plausible range (10 to 1,000 mg/dL or 0.5 to 55 mmol/L) and reports the count, mean, median, lowest, highest and sample standard deviation for each box and for all readings together. It also counts readings below 70 mg/dL (3.9 mmol/L), the threshold used in the NIDDK hypoglycemia guidance and in the ADA standards.
Worked example. Fasting: 98, 105, 112, 121, 94, 108, 117. The sum is 755, so the mean is 755 ÷ 7 = 107.9 mg/dL, the median is 108 and the range is 94 to 121. Other readings: 168, 204, 185, 142, 66 give a mean of 153.0 mg/dL and one reading below 70. All 12 readings average 126.7 mg/dL.
Use and limits. This is arithmetic on what you type. It does not say whether a number is good or bad, and an average hides the lows and highs that matter. When you are ill, follow the sick-day plan your care team gave you, and share the log with them. No ads or third-party scripts load on this page and nothing is sent anywhere.
Frequently asked questions
How do I average my fasting glucose readings?
Add the readings and divide by how many there are. Seven readings that add up to 755 mg/dL average 755 / 7 = 107.9 mg/dL.
Why show the median and the spread as well as the mean?
An average can hide a few very high or very low readings. The median is less affected by outliers and the standard deviation shows how spread out the readings are.
Does this page tell me if my readings are in a healthy range?
No. It only does arithmetic. It counts readings below 70 mg/dL (3.9 mmol/L), the threshold NIDDK and the ADA use for low glucose, but targets are personal. Ask your care team.
Is the log stored or sent anywhere?
No. The calculation runs in your browser and nothing is uploaded or saved. This page loads no ads or third-party scripts.
Sources
Checked
- NIDDK: Low Blood Glucose (Hypoglycemia)
- American Diabetes Association: Section 6, Glycemic Goals and Hypoglycemia, Summary of Recommendations (Clinical Diabetes, 2025)
Runs entirely in your browser. Nothing you type is sent or stored.
Educational worked example, not medical advice
This page shows arithmetic and published rules of thumb for learning. It is not a dosing instruction, a diagnosis or a treatment plan, and it does not know your insulin, your body or your health history. Never change insulin or medicine because of a number on this page. Confirm every setting and target with your diabetes care team. If you have symptoms of a very low or very high glucose, follow your care plan; in an emergency call your local emergency number.