Just put a $ before the letter and/or number you don't want to change.
$A1*C1
will keep A constant
A$1*C1
will keep 1 constant and so on.

Remember that normally letter changes if your drag to right and number
changes when you drag down...

So if you are dragging down
A$1 is same as $A$1 but different when dragged right

"robdanjoe" wrote:

How do i click and drag a formula while keeping one of the values constant?

ie:
A1*C1
A1*C2
A1*C3

etc,