You can calculate this with the RATE function by filling its five fields — Nper (number of periods - 12), Pmt (periodic investment – 5000 with a minus sign), Pv (present value – 0), Fv ...

The XIRR function takes into account the cash flows, the dates, and a guess of the IRR to instantly compute the internal rate of return. In this example, 0.2 -- 20% -- was used as the IRR estimate ...