How to avoid manually entering this formula in Excel

Question

I'm trying to calculate a value called, "additional throughput". It is calculated by subtracting the base case module's throughput from a new module's throughput.

In the sheet below you can see that for the third row down (has a blue box in it), that the additional throughput is calculated by the formula "=T6-T4".

The problem is that when I click on this box and drag it down to apply the same formula to the other rows, I want the formula to become "=T7-T4" for the next row. Instead it becomes "=T7-T5". I tried to select multiple cells (where the formula was manually entered) before dragging down so it could recognize that the T4 doesn't change, only the first part. However, that didn't work.

Answer 1

In Excel you can use $ signs before the column or row references to make those references "absolute" (rather than "relative"). For example if you use =A$1 then the 1 doesn't change when you copy down. If you use =$A1 then the A doesn't change when you copy across. If you use =$A$1 then neither changes whichever way you go.

So for your case you need to use

=T6-T$4

when you copy that down T$4 doesn't change

Answer 2

You have to make the cell address of T4absolute by pressing F4, so it becomes $T$4. When you then copy the formular to other places T4 will keep its absolute address.

Answer 3

I figured it out. You put a $ symbol in front of the row and column you want to not change. This is referred to as an absolute reference.

Found out how to do it here:

How do I change an Excel relative cell to an absolute cell?