My company often needs to know how much material there is on a particular
roll and seeing as some of them are over 500 feet in lenght when they get
here, rolling them out is not an option.

Using the following example, I would appreciate if you could tell me whether
this can be formulated or if I need to do this in vba.

This is what I did to measure one, as you can see it's effective but
impractical.

Total diameter - 210 mm, Core diameter (there is no material in here) 89mm,
Thickness of material 0.25mm.

I started by calculating the radius (105mm) minus the core's radius 45mm)
giving me a useable radius of 60mm. Divided that by .25 giving me 240
"loops" around the core.

This is where it gets impractical. I created 240 cells where each cell in
column A would be Pi*Diameter, and increasing the diameter by .5mm every
cell, representing the added thickness of .25mm on both sides of the core.
Then added all 240 cells giving me the total length in material.

I know in VBA I could use a loop function and it would be fine, but I'm
really hoping I can have it as a 1line formula that takes the information
entered in various cells and calculate on the spot.

Am I dreaming? Help is much appreciated.