Oh, nice, I think that CAGR formula is what I was looking for. That seems like the proper way to track performance over time. I’m too lazy to record every contribution and withdrawal, so for my tracking sheet I just calculate the total for the year, then assume it happened evenly throughout the year. When I was working I made most contributions through paycheck deductions, so that is a pretty good approximation.
Since I don’t feel like transferring everything over, I don’t think I’ll start using that bogleheads spreadsheet, but that seems like a really good tool.