Calculator
Plateau checker
Paste your weekly weights and the week you started logging. The checker measures your recent rate of change as a slope, compares it with an illustrative curve scaled to the published endpoint for semaglutide 2.4 mg or tirzepatide 5, 10 or 15 mg at the same point on therapy, and tells you whether you are flat, slower, in line or faster, with the caveat that averages are not individuals.
What it computes
Your weekly weights against an illustrative curve scaled to a STEP 1 or SURMOUNT-1 endpoint.
Never pre-fills a dose
Your weights
Pick the agent you are prescribed. The comparison uses an illustrative curve scaled to that arm’s endpoint; it does not identify your product or dose.
Count from your first injection. Enter 0 if the first weight below is your starting weight.
One per week, same scale, same time of day. Separate with commas, spaces or new lines. Four or more weeks gives a usable rate; eight or more is better.
0 weights read.
Rate check
Enter the week you started logging and at least two weekly weights. The checker compares your recent entries with an illustrative curve for the same weeks on therapy.
| Week on therapy | Cumulative change (%) | Rate over prior 4 weeks (% / week) |
|---|---|---|
| 4 | -2.4 | -0.59 |
| 8 | -4.4 | -0.5 |
| 12 | -6.1 | -0.43 |
| 16 | -7.5 | -0.36 |
| 20 | -8.8 | -0.31 |
| 24 | -9.8 | -0.26 |
| 28 | -10.7 | -0.23 |
| 32 | -11.5 | -0.19 |
| 36 | -12.2 | -0.16 |
| 40 | -12.7 | -0.14 |
| 44 | -13.2 | -0.12 |
| 48 | -13.6 | -0.1 |
| 52 | -14 | -0.09 |
| 56 | -14.3 | -0.07 |
| 60 | -14.5 | -0.06 |
| 64 | -14.7 | -0.05 |
| 68 | -14.9 | -0.05 |
Formulashown in full, nothing hidden
your % change at entry i = (w_i - w_0) / w_0 x 100
your rate (% / week) = least-squares slope of the last 4 entries against week number
illustrative cumulative % at week t = endpoint % x (1 - exp(-k t)) / (1 - exp(-k T)), k = 0.04, T = trial endpoint week
illustrative rate (% / week) = (cumulative % at week end - cumulative % at week start) / weeks
verdict: fewer than 3 intervals = insufficient; window total above +0.5% = gaining; within +/-0.5% = flat;
otherwise observed / expected below 0.5 = slower, 0.5 to 1.5 = in line, above 1.5 = fasterThe trial endpoints are measured: STEP 1 semaglutide 2.4 mg, -14.9 percent at week 68 (placebo -2.4; PubMed 33567185); SURMOUNT-1 tirzepatide 5, 10 and 15 mg, -15.0, -19.5 and -20.9 percent at week 72 (placebo -3.1; PubMed 35658024). The curve between week 0 and the endpoint is a first-order model with an assumed rate constant of 0.04 per week. It was not fitted or validated against the published trial trajectories. Its intermediate values are illustrative, not measured weekly trial averages.
Averages hide spread. In STEP 1, 86.4 percent of the semaglutide group lost 5 percent or more and 32 percent lost 20 percent or more; in SURMOUNT-1 at 15 mg, 91 percent lost 5 percent or more and 57 percent lost 20 percent or more. The rest lost less. Those endpoint thresholds do not establish where a participant fell relative to this illustrative weekly curve.
Assumptions, checked September 4, 2026what the arithmetic takes as given
- Entries are assumed one week apart, on the same scale, at the same time of day. Irregular gaps make the slope wrong.
- The flat band (0.5 percent of body weight over about four weeks) and the 0.5x and 1.5x ratio cut-offs are working conventions of this tool so that a verdict can be given. They are tool conventions, not clinical definitions of a plateau.
- The illustrative curve is a first-order interpolation between week 0 and the published endpoint; the papers publish figures, not weekly tables, so intermediate values are modelled. Beyond the trial endpoint the curve is held flat because nothing was measured.
- Trial participants received diet and activity counselling (500 kcal/day deficit, 150 min/week) and dose escalation on the label schedule. A slower titration, a different dose, missed doses or a compounded product of uncertain content all move an individual away from the trial mean. Compounded GLP-1s are not FDA approved and are not interchangeable with brand products.
- This tool never suggests a dose change. Its output is a comparison and a set of things to discuss with a prescriber.
This calculator is an arithmetic aid for medication a licensed prescriber has already prescribed. It does not recommend a dose. Confirm any result with your prescriber or pharmacist before use.
Read before you use it
Guides for this calculator
Educational, not medical advice. Read the medical disclaimer.