Automatically numbering squares in grid maps?

[Sapiento]

What the title says. Does anyone know a program that creates grid maps where the squares are numbered automatically, A1 or T43, like that?

[ravells]

I think Campaign Cartographer does (and with Hexes too), but I don't know any free ones.

I just had an idea and it works. You can do it in Microsoft Excel (not sure about the open office version, but I presume you can in that too).

Under the page layout menu tick 'print guidelines'
Set your column and row widths / heights to something reasonable large like 80 px.
Type in the first number in the row column (presumably 1) and use the drag to create a series to do the rest in that row or column.
Repeat for each Row / Column until you have them all (couldn't find a quicker way, but there must be one - formulae?)
Export / print it as a .pdf (download cute pdf writer for free)
Import it into Inkscape together with your map and overlay it over the top.

[Sapiento]

Thank you, ravs.
I have to check CC and Excel for this.