This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
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.
That is where I would start, not where I would stop.
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.
Happy to be the one who is wrong here if it settles the question.
The arithmetic in post #30 is right; the assumption feeding it is the part to check.
Maintaining a calculator means checking the arithmetic against hand-worked cases at each review, not checking that it still loads.
Answering the question post #32 raises rather than the one it answers.
Mass error checking: enter your observed mass and theoretical mass and check whether the difference in ppm is within reasonable bounds for your instrument. Useful sanity check on LC-MS results.
This is the version I would want a new member to read first.
Rounding behaviour is where two tools disagree. One rounding to the nearest graduation and one to two decimal places will produce different advice from identical inputs.
A weak preference rather than a position.
Precision and significant figures: the calculators do not round to match your input precision. If you input values to one decimal place, the output might have more. Use significant figures appropriate to your input precision.
Narrowing post #34, because the general version has more than one answer.
Significant figures in the output should not exceed what the inputs support. A concentration calculated from a nominal vial mass is not known to four decimal places.
Adding the caveat now so it does not have to be extracted later.
Useful. I have added it to my own notes with the date on it.
The most common input error is entering the vial mass in the concentration field. It produces a plausible number, which is why it survives.
Post #36 and I disagree about the size of the effect, not about the direction.
Unit-conversion tools are only as good as the assumption they make about the syringe. Ask what barrel and what graduation interval it assumed before trusting the units figure.
Written in the hope of being told what I have missed.
Coming back to post #37, because the follow-up matters more than the original answer.
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.
The number is defensible. The precision I gave it is not.
Post #41 is right about the mechanism and I think understates the practical bit.
Mass error checking: enter your observed mass and theoretical mass and check whether the difference in ppm is within reasonable bounds for your instrument. Useful sanity check on LC-MS results.
The strength of my opinion here exceeds the strength of my evidence.
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.
Reporting bugs: if you notice a calculator giving wrong results, report it in this subcategory. Bugs are fixed when identified.
Good question, well framed, and I would like to see it answered properly.
A saved calculation is worth more than a remembered one. Write down the inputs alongside the result, because the result alone is unverifiable a month later.
The reconstitution calculation is total mass divided by total volume for concentration, then dose divided by concentration for volume, then volume times one hundred for units on a U-100 barrel. Three steps, and every error is in one of them.
Nothing above should be read as advice about what anyone else should do.
Tools that run entirely in the browser send nothing anywhere, which matters more to some people here than others and is worth stating either way.
A calculator that shows its working is worth ten that give an answer. The whole value is being able to see which step you disagree with.
Filing this under things that are true until someone shows me otherwise.
Post #49 is the version of this I will quote in future. One addition.
Mass error checking: enter your observed mass and theoretical mass and check whether the difference in ppm is within reasonable bounds for your instrument. Useful sanity check on LC-MS results.
Worth saying I have only my own numbers here, and n is small.
Where I part company with post #50, and it is a narrow parting.
Maintaining a calculator means checking the arithmetic against hand-worked cases at each review, not checking that it still loads.
I keep a log of this specifically because memory is unreliable about it.
Unit-conversion tools are only as good as the assumption they make about the syringe. Ask what barrel and what graduation interval it assumed before trusting the units figure.
One case, stated as one case.
No disagreement from me. Posting only so the question does not look ignored.
Post #55 put the caveat in the right place and I want to underline it.
Precision and significant figures: the calculators do not round to match your input precision. If you input values to one decimal place, the output might have more. Use significant figures appropriate to your input precision.
Take it as a starting point and not as a specification.
The arithmetic in post #56 is right; the assumption feeding it is the part to check.
A calculator that shows its working is worth ten that give an answer. The whole value is being able to see which step you disagree with.
One more caveat and then I will stop qualifying: the sample selected itself.
Significant figures in the output should not exceed what the inputs support. A concentration calculated from a nominal vial mass is not known to four decimal places.
I would want the raw data before agreeing with my own summary of it.
The most common input error is entering the vial mass in the concentration field. It produces a plausible number, which is why it survives.