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Data & Tools · Calculators · continued

Second pass at: The mass-error checker and its intended scope posts 31–60

This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.

K
KStephanopoulosTL3Regular4 Oct 2025#31

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.

4 likes 10mo
AK
ar.kravchenkoTL2 Moderator6 Oct 2025 · edited#32
plateau_notes, post #4: 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. Go to post

post #31 is right about the mechanism and I think understates the practical bit.

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.

0 likes in reply to #4 10mo
EM
endpoint_marginTL27 Oct 2025#33
BT
b.teixeiraTL2 Moderator9 Oct 2025#34

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.

13 likes 10mo
CI
citation_indexTL2Member10 Oct 2025#35
a.nascimento, post #9: 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. Go to post

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

2 likes in reply to #9 10mo
AK
a.kravchenkoTL2 Moderator11 Oct 2025#36
h.ramos, post #1: Posting this under the heading it deserves: Second pass at: The mass-error checker and its intended scope Everything below is what sits behind that. Working through the identity arithmetic and I would like it checked. tirzepatide has a monoisotopic mass close to 4813.5 Da. On an electrospray instrument I would expect to see the multiply… Go to post

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.

0 likes in reply to #1 10mo
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GSwinburneTL1Member13 Oct 2025#37

Coming back to post #35, because the follow-up matters more than the original answer.

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.

20 likes 9mo
MO
m.oyelaranTL2 Moderator14 Oct 2025#38

Picking up post #35: that is the part I would want checked first.

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.

8 likes 9mo
CD
cohort_driftTL3Regular15 Oct 2025#39
buffer_sheet, post #22: 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. Go to post

Worth separating two things that post #35 runs together.

Units: all calculators explicitly require units to be stated. This prevents the decimal-point errors that come from forgetting units. Always verify units in and out.

0 likes in reply to #22 9mo
IO
i.oseiTL2 Moderator16 Oct 2025#40
Ziegler, post #14: post #13 is right about the mechanism and I think understates the practical bit. 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. Go to post

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.

0 likes in reply to #14 9mo
CT
c.tullochTL2 Moderator18 Oct 2025#41

post #40 is right about the mechanism and I think understates the practical bit.

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

2 likes 9mo
DO
d.oyelaranTL3Pharmacist19 Oct 2025 · edited#42

Worth separating two things that post #38 runs together.

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.

8 likes 9mo
NK
n.krastevTL2 Moderator20 Oct 2025#43
p.diallo, post #23: 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. Go to post

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.

20 likes in reply to #23 9mo
BD
baseline_driftTL2Analytical chemist22 Oct 2025#44

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.

0 likes 9mo
IA
id.almeidaTL2 Moderator23 Oct 2025#45

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.

0 likes 9mo
BV
bias_varianceTL424 Oct 2025#46
JI
j.iyerTL2 Moderator25 Oct 2025#47
gradient_file, post #20: 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. Go to post

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.

14 likes in reply to #20 9mo
B
batchlogTL3Regular27 Oct 2025#48
KStephanopoulos, post #31: 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. Go to post

Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.

The correction was fair and I had been repeating something I had not checked carefully enough.

28 likes in reply to #31 9mo
SK
s.kuuselaTL2 Moderator28 Oct 2025 · edited#49

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.

8 likes 9mo
TY
two_year_lineTL3Regular29 Oct 2025#50

Units: all calculators explicitly require units to be stated. This prevents the decimal-point errors that come from forgetting units. Always verify units in and out.

19 likes 9mo
MR
m.ramosTL2 Moderator30 Oct 2025#51

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.

0 likes 9mo
BO
b.oylerTL1Member1 Nov 2025#52
m.oyelaran, post #38: Picking up post #35: that is the part I would want checked first. 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. Go to post

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

0 likes in reply to #38 9mo
JI
j.ivaturiTL2 Moderator2 Nov 2025#53

On post #49 — agreed on the reasoning, with one qualification.

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.

18 likes 9mo
RH
revision_historyTL3Wiki editor3 Nov 2025 · edited#54

post #53 answers the question as asked. The question underneath it is different.

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.

7 likes 9mo
FF
f.fontaineTL2 Moderator4 Nov 2025#55

I read post #53 twice before replying, because I had assumed the opposite.

Two things before anyone answers the substance.

First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound.

0 likes 9mo
GV
g.valckenaereTL3Regular5 Nov 2025#56

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.

26 likes 9mo
SR
s.roosTL2 Moderator7 Nov 2025#57
p.diallo, post #23: 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. Go to post

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.

13 likes in reply to #23 9mo
DN
desiccant_notesTL2Member8 Nov 2025 · edited#58

post #57 is right about the mechanism and I think understates the practical bit.

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.

4 likes 9mo
GE
g.ekstromTL2 Moderator9 Nov 2025#59
baseline_drift, post #44: 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. Go to post

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.

4 likes in reply to #44 9mo
L
LeitermanTL3Regular10 Nov 2025#60
KStephanopoulos, post #31: 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. Go to post

Picking up post #57: that is the part I would want checked first.

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.

0 likes in reply to #31 9mo