Running Inventory

[Sorna2020]

I am creating a running inventory sheet. In most of the cells, there will be a serial number that I need to count as -1 from inventory count. In stock will be calculated separately, I need to continually subtract from In Stock to get my Available total.
What formula should I use?
In example: All sites will have either Hardware 1 or Hardware 2. Most (but not always) will have a PC and Printer too. I am guessing I need to use =IF(ISBLANK) but I have never used that formula before. How do I set up for list of about 100 lines?


[TABLE="class: grid, width: 500, align: center"]
<tbody>[TR]
[TD]A[/TD]
[TD]B[/TD]
[TD]C[/TD]
[TD]D[/TD]
[TD]E[/TD]
[TD]F[/TD]
[/TR]
[TR]
[TD]1[/TD]
[TD]Inventory:[/TD]
[TD]Hardware 1[/TD]
[TD]Hardware 2[/TD]
[TD]PC[/TD]
[TD]Printer[/TD]
[/TR]
[TR]
[TD]2[/TD]
[TD]In Stock[/TD]
[TD]10[/TD]
[TD]14[/TD]
[TD]8[/TD]
[TD]7[/TD]
[/TR]
[TR]
[TD]3[/TD]
[TD]Available[/TD]
[TD]8[/TD]
[TD]12[/TD]
[TD]4[/TD]
[TD]3[/TD]
[/TR]
[TR]
[TD]4 [/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]5[/TD]
[TD]Hospital 1[/TD]
[TD="align: center"]1[/TD]
[TD][/TD]
[TD]XYZ1234XYZ[/TD]
[TD]ABC4321ABC[/TD]
[/TR]
[TR]
[TD]6[/TD]
[TD]Hospital 2[/TD]
[TD="align: center"][/TD]
[TD="align: center"]1[/TD]
[TD]UVW1234UVW[/TD]
[TD][/TD]
[/TR]
[TR]
[TD]7[/TD]
[TD]Hospital 3[/TD]
[TD="align: center"][/TD]
[TD="align: center"]1[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]8[/TD]
[TD]Hospital 4[/TD]
[TD="align: center"]1[/TD]
[TD="align: center"][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]9[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]10 [/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]11[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]

[TABLE="align: left"]
<tbody>[TR]
[TD][/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]

 

[AFPathfinder]

I'd suggest subtracting the value in row 2 by the COUNTA of all values in columns using serial #s instead of counts. Such as a formula in cell E3:

=E2-COUNTA(E5:E500")