=sum([first sheet]:[last sheet]![cell])

One practice I use for this sort of thing is to create a 'first' and 'last'
sheet and then sum everything between these two. Advantages a
1. you can change the sheet order without messing up the sum.
2. you can move sheets into and out of the total by just dragging them to a
point after 'last' sheet.
3. keeps it simple when checking if tabs are 'in' or 'out' of the calculation.

So: =sum(First:Last!A1)

HTH

Giz

"JamesHenry" wrote:

Hi,

I have a workbook that has 30 sheets in it, I want to add up the same cell
no across all 30 sheets to give me a total.

how do you do this??

James