Hi,

I have a saving plan, that work this way:
1200€ yearly deposit, that each year got incremented by 3%
The median interest rate is 4%
How much will I have after 20 years?

And how to put the math down on a spreadsheet?

For those curious about it, it's a mixed insurance/retirement plan that I subscridbed 7 years ago when working for an insurance company.

Not quite sure I got it exactly right, but I'm getting 48,049.

For excel, you need four columns:
1) Year (1, 2, 3, 4..... to 20)
2) Starting amount (0 in year 1, ending amount from previous year thereafter)
3) Deposit (1200 in year 1, 1.03*previous deposit thereafter)
4) Ending amount ((starting amount + deposit)*1.04)

For the first row, you have year = 1, start = 0, deposit = 1200, end = (0+1200)*1.04 = 1248.

Every row after that, year = prev year + 1, start = prev end, deposit = (prev deposit)*1.03, end = (start+deposit)*1.04.

With those parameters, you have 48,049 after 20 years.

thanks a lot! It's exactly the formula I needed!