I am trying to calculate the % of a sale to overall sales as a row formula. In the following blog entry:  https://www.zoho.com/reports/blog/explore-zoho-reports-series-part-i-formula-column.html it provides the following instructions:

Or say you want to calculate the percentage of a sale value to overall sales. The formula will be  (“Sales”/Sum(“Sales”))*100

However, If I try to add this formula as a custom formula it throws an error "Please use aggregate formula option to create aggregate formula.

And if I try to add this formula as an aggregate formula it throws an error: "Mixing of Aggregate functions (like SUM,MAX, ...) with no aggregate columns is not allowed.

Could you please let me know what I am doing wrong?

Thanks,

Pete