User Input to calculate change to number column?


I have built a system tracks medications and supplements used in my household, and lets me know when to refill and how much I need. I’m looking for an easy way to make corrections when the calculated amount leftover doesn’t match reality during the check.

More details:

It’s essentially an inventory system that uses preset consumption amounts to prompt me when to replenish the supply. When I check the supply each month, I find that occasionally the real consumption amount is different than predicted, and I need to adjust the number for the amount leftover before replenishment. However, that amount is calculated so I can’t adjust it manually.

Table details:
Each row includes the following columns (among others):
A. Name of Pill (Text)
B. Amount in container (#)
C. Number of loose pills on hand at start of month (#)
D. Number of containers on hand at start of month (#)
E. Total number of pills on hand at start of month ( C+D)
F. Amount used monthly ( calculated from other columns)
G. Total number of pills leftover at end of month ( E–F)

Example scenarios:

  • I take 2 multivitamins a day, and the bottle contains 100 pills. At the end of the month (30 days) I should have 40 left (100-(2*30)), however, I forgot to take it a a few times so I actually have 45 left.
  • My cat takes 1 calming pill per day, but I took her to the vet a couple times and used some extra ones. The bottle contains 90 pills for 90-day supply. When I tally up at the end of the second month, I see I have 25 left instead of 30.

In the first case I need to add to the ending total, and in the second I need to subtract.

Current approach:
What I’m doing now is adjusting the one number that can be manually entered (column C) which requires me to stop my inventory and do some math – not my strong suit.

What I want:

Ideally I would hit a button, enter the true amount leftover, and have a formula figure out the difference and adjust it.

How would you do this within a row?

Thanks in advance,


Could you tell me for the bulk quantity what exactly it corresponds to pls? I have a good idea to solve your concern but to make it as fair as possible, I need to be sure of the source.
What I mean is, is it leftover medication from the previous month or is it an accumulation of medication that was not taken and therefore adds to your final total?



This is obviously a solution just for you and not for your cat but the principle remains the same and you will just have to enter in the form each pill intake and you will get at the end a number of pills left for you and your cat :slight_smile:

I’m not an expert in this field so I could be wrong on how to proceed but I have no doubt that one of the champions will correct it in the worst case :slight_smile:



Hi @little-island :blush: !

I have another suggestion which is still similar than what @Thierryvm proposed though but instead of a button, why not use sliders ? :innocent:

Because I don’t have enough info about your actual setup, I voluntarily left out the theoretical “per month posology” and the numbers of containers but the small sample here should be enough to see if this could work for you :blush:

In the sample, you’ll find a Correction slider which should allow you to manipulate the total of pills left …
I set the minimum of the slider to Minus (-) 1/2 Pills/Container and the maximum to Plus (+) 1/2 Pills/Container which I had to calculate in 2 columns because for some reasons (:thinking: ) I couldn’t make it work within the Slider settings… But those 2 columns can be hidden and/or modified to your liking :blush:

The formula to determine the Minimum is :

  (0 - thisRow.[Pills/Container])/2,
  (0 - thisRow.[Pills/Container] - 1)/2

And what it does is: if the amount in thisRow.[Pills/Container] is even, it returns (0 - thisRow.[Pills/Container])/2 (so a negative 1/2 Pills/Container) … else (if the amount is odd), (0 - thisRow.[Pills/Container] - 1)/2 (so a negative 1/2 Pills/Container - 1) to avoid decimals :blush:

The maximum formula works in the same way :blush:

With this slider you can then correct the totals of pills from a negative amount (if you needed more) to a positive one (if you needed less or forgot) :blush:
(the default correction value of the slider is set to 0)

To correct your totals of pills, you would just have to add the value from the slider to your desired total formula (as if the slider is a negative value, it will subtract the value, if it’s positive, it will add it and if there’s no correction to make and the slider value is then 0, the total will just add 0 so it won’t change) :blush:

In my simplified sample the Total Pills formula is then :

thisRow.[Pills/Container] + thisRow.[Loose Pills - Start of Month] + thisRow.Correction

You could use a similar slider for your Loose Pills too :blush: or even potentially get rid of it and solely use one slider (but that depends on the your doc, your needs/wishes :blush: )

If you could share a sample/mock-up doc (with anonymised datas) we could probably give you a more precise answer :blush:


Excellent approach, I thought of the same thing when I realized the dosage constraints but I still don’t master the formulas well :frowning:
This is exactly what I like about this community and I thank you for this shared experience.

Best regards,



Thanks to you both for taking the time to offer suggestions.

I like the idea of using a slider, and it’s clever how you’ve calculated the range. However, I don’t want to enter the difference between the numbers, I want to have the difference calculated for me. Also it could be cumbersome to interact with a slider considering the numbers are going to be anywhere from under ten into the hundreds, I think I might as well just type in a number if I have it.

I see your approach is to add columns to handle the information. I was kind of hoping there was some other kind of input control I could use rather than adding new columns, but I guess not!

With columns, I could make one column to enter the true leftover number into, and create a column containing an action that uses that value to correct the starting number, then resets the helper column to zero.

Then, I could either press a button to immediately run the action (my preference), or I could chain it into the actions that happen when I press the button at the end of the month to calculate the new inventory.

Hm… This should work!

Thanks again! This really is a great community.


Hello :),

In my version, everything is calculated automatically but the problem is that it is on a fixed dosage and therefore requires two tables.
But, I am convinced that there is better to propose to answer your needs, I do not master enough the formulas for the moment :frowning:





To finish and answer your problem, here is a functional solution (with the help of @Christiaan_Huizer ) which is based as you wanted on the use of a button.
The stock is managed and you just have to add the consumption and you use the method listed above to complete your tables.

Sincerely yours,


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I’m glad to know those suggestions gave you ideas :grin: !

Thank you :blush: !

I have no doubt that it’ll come :wink: … There are still many things I don’t master pretty well (or at all) and I can say that being here trying to help others really helped me to move forward on my own learning curve :blush: (I still couldn’t grasp FormulaMap() not that long ago :innocent: )

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@Thierryvm, that’s basically what I did!

I added a number column called “True Total Leftover”, and a button column called “Adjust Leftover”.

Here’s a sample of it in play (Display column and others aren’t shown. I’ve added the ƒ character to the names of the columns that are calculated.) :

The button does this:

  1. Finds the difference between the calculated total leftover and the “true” total leftover
  2. Adds that value to the Loose on Hand value
  3. Replaces the value in the Loose on Hand column with this new value
  4. Replaces the value in the “True Total Leftover” with a blank value

The formula is:
thisRow.[Loose on Hand] + (thisRow.[True Total Leftover] - thisRow.[Total Leftover ƒ])

Since there isn’t really a way (AFAIK) to alert the user that the button requires a value in the column next door, I set the button options to be disabled if the column is blank.

The reason I had to adjust the Loose on Hand number (instead of the leftover number itself) is because of the way the values are formulated:

  • Total on Hand to Start = Loose pills on hand + (Containers on Hand * Amount per Container)
  • Loose pills Leftover = Total Leftover - (Containers Leftover * Amount per Container)
  • Total Leftover = Total on Hand to Start - Amt planned for use per 4-weeks
  • (Per 4-week is calculated from the frequency in the plan, columns not shown here)

What this means is, at the start of the month I can manually enter/adjust Containers and Loose pills on Hand. And at the end of the month I can adjust the Containers leftover, but Total leftover and Loose Leftover aren’t manually adjustable.

But if we adjust the Loose on Hand, it trickles down, so to speak, to the Total Leftover.

Then at the start of the next month, I move the Loose Leftover and Containers leftover to their corresponding “On hand” columns and we start all over again! (I have an action for this.)

I also didn’t mention that there are several supporting tables that this table looks up values from (including the number of pills in the container). This is one reason why I haven’t posted an anonymized copy – that alone would be a bear to create. It’s a hugely complex system, but it’s really helping me wrangle the pill situation here!

Thanks again for the ideas and such. I hope this helps someone else sometime, too.


Here are the button options:

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I understand better the objective now :). I’m a beginner on Coda and I’m using the community space a bit as a form of learning by trying to help people as best as I can to find a solution to the problems they encounter with Coda.

It’s by sharing this way that Coda becomes more than a tool and that it becomes possible to learn a programming logic which is not always simple :).
I hope in any case that my participation will have helped you even a little ^^.




i strongly endorse and aplaud this approach to learning coda.

well done, @Thierryvm, this will serve both yourself and the community.

i commend this approach to all of us who are on this journey of discovery.



Thanks a lot @Xyzor_Max,

It means a lot to me because I don’t have the experience of a professional user and I admit that helping out has always been rewarding for me.

I’m aware that I’m not yet at the level to give the best answers but as you pointed out it’s by helping that we’ll move forward the best together.

In this spirit, I have started to create a tutorial to present Coda in French because it is not well known on the French side and I have also created a Discord server (Coda French) CODA FRENCH to help the French community that does not speak English like me :frowning:



for a maker who does not speak english (if i understand you correctly), you are participating in this forum very well indeed.

may i ask what method you use to effect such clear communications?


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Hello @Xyzor_Max ,

I use DeepL (, much better than google translate :slight_smile:



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