Is there a fast way of calculating the discounted payback period rather than writing it out manually for each year?

yeah. use your calculator. also, note that u can calculate discounted payback on TI BAII PLUS PRO and not on the non-pro version.

I’m still using the calculator - for each year I calculate the discounted cashflow and write it out that way.

But that’s unfortunate that it’s not a function of the HP, hence my question, maybe I’m overlooking something. I’m aware of the TI functionality, but I don’t have it.