Which financial formula do I use?
 

If I have a lump sum of money and I wish to use 4% of it a year. And each
year I'll increase
my withdrawal to keep up with inflation. Which financial formula do I use?
Is it NPV?
If so do I add the lump sum as a negative number or do I add it at the end
of the formula
as a +? If a financial formula is not the answer, how do I set up a
spreadsheet?
Thank You
Ted