That is…

=todayDate+(absoluteValue(netWorth)/(overallChange/(todayDate-beginDate)))

Or, in English, I take the absolute value of my net worth (since it’s negative – if it were positive and I was shooting for a wealth goal instead, I wouldn’t need to do that), divide that by the result of the division of my overall change by the difference in dates from when I started to now, and add today’s date. I think I said that right. End result is figuring the overall average daily increase, dividing that by my net worth to figure the number of days it’ll take to get to zero, and add that number of days to today’s date.

I’m like Will Hunting (a la Good Will Hunting, der) when it comes to figuring crazy ass spreadsheet formulae. I’ve come up with ones 1000x more complex than that that appeared to be correct.

If you like, I can email you that sheet so you can fiddle with it yourself.