**Re: Request for help with sumif formula**
OK, so there are probably lots of ways of doing this.

If I was doing it myself, I think I would use separate helper rows to

a) identify which year the replacements happen, and

b) calculate the replacement costs in those years

Some people are not keen on helper columns / rows, but I think they make it easier to check the calculations.

And once you've set them up, you can hide them if you don't want to see them - either just hide the rows, or place them on a completely separate sheet and hide that if you like.

So here goes.

To identify the years in which replacement is required, for "Furnace", use something like

Code:

`=IF(H$1< $F2,0,IF(MOD((H$1-$F2),$D2)=0,1,0))`

Let's say you put this in H12, and copy across to the right as far as required.

This should give you a string of mostly 0s, with the occasional 1, in year 2, year 14, and so on.

This identifies which years see a replacement.

Then have another formula, like this

and again, copy across as far as required.

This puts 4000 into each year that a new furnace is required.

Then your required results in row 11 are the sum of your monthly cost, PLUS the replacement cost (if any) identified in the second formula I've given you.