A calculator that gives a right answer to the wrong question — does this still hold?

A calculator that gives a right answer to the wrong question — does this still hold? I have a specific reason for asking rather than idle curiosity, and the context is below.

I would like to understand what this number means before I repeat it anywhere.

A Janoshik report on a semaglutide lot gives 97.4% purity. The supplier certificate for the same lot states 98.4%. Both documents name a reversed-phase method; neither states the same gradient.

My question is not "who is right". It is: given that those two figures were produced by different methods, what is the largest difference I should expect from method alone, and at what point does a gap stop being explainable that way?

The calculators maintained on this site are open-source and verifiable. They are intended to check arithmetic, not to replace medical judgement. Using them is optional and they are provided for convenience.

Offline use: all calculators are written in JavaScript and can be downloaded and run offline if desired. They do not require internet connectivity to function.

Picking up post #2: that is the part I would want checked first.

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

Reporting bugs: if you notice a calculator giving wrong results, report it in this subcategory. Bugs are fixed when identified.

This follows post #5 rather than contradicting it.

Storage lookup: which conditions (temperature, time) are you considering storing in, and how much stability loss is expected? The calculator gives a rough estimate based on typical stability data. Not a substitute for your compound's specific stability data.

Dose equivalence calculator: compounds have different potencies. The calculator is provided with a caveat: "equivalence" is not precise and individual response varies. It is a rough starting point, not a dose prescription.

Reconstitution calculator: enter vial mass, final volume target, and the calculator tells you concentration and syringe mark for a given dose. Useful for double-checking arithmetic when you are doing it by hand.

Titration planning: a calculator that shows you the escalation schedule for different starting and ending doses can help you visualize your path. Actual path might be slower or adjusted for tolerability.

This follows post #10 rather than contradicting it.

Why calculators are not medical advice: they do arithmetic. Medical decisions are not arithmetic. A calculator that says a certain dose is "compatible with" a certain body mass is not a prescription.

I read post #12 twice before replying, because I had assumed the opposite.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.