How we calculate your numbers

This is the ADAG equation (Nathan et al., 2008), the same relationship used to translate an average glucose into a familiar A1C-style percentage. We compute it from the mean of your readings over the period you are viewing.

It is an estimate from your own logs, not a blood draw, so it moves as you add readings and can differ a little from a lab result. More readings, spread across the day, make it more representative.

GMI is the metric printed on standard Ambulatory Glucose Profile reports (Bergenstal et al., 2018), the CGM-era companion to estimated A1C. It answers a similar question from a slightly different angle.

Because they are built differently, GMI and a lab A1C often differ by a few tenths of a percent. That gap is normal, and the difference can itself be informative for you and your clinician.

The simplest and most honest of the numbers: the share of your readings that land inside the target band you set (a common starting band is 70 to 180 mg/dL, adjustable in Settings).

The widely cited consensus goal is above 70%, but the right target is a conversation for you and your clinician.

Variability captures the size of your swings, separate from where they settle on average. Because it is a ratio it carries no units, reading the same whether you use mg/dL or mmol/L.

A coefficient of variation of 36% or below is a common stability goal. Two people can share an average yet live very different days if one swings far more than the other.

The standard body-mass index. We store height and weight in metric and convert for display, so the value is identical whether you enter centimeters and kilograms or feet and pounds.

Categories follow the usual reference points: under 18.5 underweight, 18.5 to 24.9 typical, 25 to 29.9 overweight, 30 and above obese. BMI is a rough screen, not a verdict on any one person.

You choose mg/dL or mmol/L once, and every reading, average, and target uses it consistently. Conversions apply the exact factor above and happen only for display, never stored twice, so a number never drifts through rounding.

A wrong conversion on a health number would undermine the whole point of the app, so unit conversion is one of the most heavily tested parts of the code.

The pages that explain a specific reading or A1C value use the American Diabetes Association diagnostic criteria: fasting 100 to 125 mg/dL, two hours after eating 140 to 199 mg/dL, and A1C 5.7 to 6.4% are prediabetes ranges; fasting 126 mg/dL, two-hour 200 mg/dL, and A1C 6.5% and above are the thresholds used in diagnosing diabetes.

These are reference ranges for education. A meter reading is not a lab test, and a diagnosis is made on laboratory results, usually confirmed on two occasions. Day to day, many people track against a wider 70 to 180 mg/dL band, which is what time in range measures.

The GLP-1 weight loss calculator projects a curve through the published end-of-trial averages (STEP 1 and 2 for semaglutide, SURMOUNT-1 and 2 for tirzepatide, SCALE for liraglutide) using an exponential time course normalized to hit each trial's mean exactly at its final week. The time constants and the middle-half band, derived from the published responder rates, are modeling choices, and they are documented on the calculator pages.

A projection is a trial average, not a prediction. Trial participants differ from any one person and individual responses vary widely, so the calculator says plainly when a goal sits beyond what the trials showed rather than extrapolating past the data.

The GLP-1 half-life visualizer draws a one-compartment model with first-order absorption: each dose contributes a Bateman curve built from exactly two label facts per molecule, the elimination half-life and the time to peak, from the FDA prescribing information (semaglutide about 7 days and 1 to 3 days to peak; tirzepatide about 5 days and 8 to 72 hours to peak; liraglutide about 13 hours and about 11 hours to peak). Doses superpose, and the curve is shown as a percent of the steady rhythm's peak.

Percent, not ng/mL, is deliberate: an absolute concentration would need bioavailability and distribution figures that public data cannot pin down for a person. The pages label model sentences and label sentences separately so the two are never blended, and the 5-half-lives clearance figure is the standard pharmacology rule of thumb, presented as such.

The Ambulatory Glucose Profile collapses every reading onto a single 24-hour day, then draws the spread per hour: the median line, the middle 50%, and the 5 to 95% envelope. Hours with fewer than 2 readings are dropped, so the curve never implies a pattern from a stray point. The PDF report and the free AGP report tool both run this same calculation.

The reference targets shown alongside it (the 70 to 180 mg/dL band, the above-70% time-in-range goal, and the 36% variability ceiling) come from the international consensus on CGM targets (Battelino et al., 2019).