Common Multiplier for Each Column while multiplying from a different column

Roger_Penny You need to fix the reference to D1 but putting $ signs before both the column and row identifier. The formula would then look like this:

=$D$1*C2

Copy this one all the way down and you'll note the D1 is fixed and that C2 becomes C3, C4 etc.

Learn more about relative and absolute cell references in the article linked to below.

https://support.microsoft.com/en-us/office/switch-between-relative-absolute-and-mixed-references-dfec08cd-ae65-4f56-839e-5f0d8d0baca9 

Alternatively, give cell D1 a name in the Name Manager or by typing it directly in the Name Box (in the top left just above the grid where it says D1 when you have selected that cell. Just type UnitCost in that box and press enter. Now you can use that name in a formula like this:

=UnitCost*C2