In Excel you can sum a whole column with
=SUM(B:B). But of course you can't use that formula in the column you want to sum, because you'll get a circular reference.
Is there an easy way of summing all the values in the column below the current cell, other than hacks such as
For reference here's someone asking the same question on ask.metafilter: http://ask.metafilter.com/65955/ExcelFilter-How-do-I-display-the-sum-within-that-column-without-resulting-in-a-circular-reference-error
The suggestion in that thread of
=SUM(B:B-B1) is essentially what I'm looking for, if only it actually worked!