time - Estimating when it's done in excel

Question

Can I, somehow, based on time stamp and how much is done, estimate time and date for when a job is complete? I got this log that a bot I've made writes in column A time [yyy-mm-dd hh:mm], and in column B it wrights how much is done. It sorts it all with newest on top.

Answer 1

Gary's answer is correct, but for convenience if the 2nd row of data can be an arbitrary progress status (not just start of task = implicitly 0%), and if you use percentage number format (or decimals) and you would like to get the end date instead of just the duration, use following formula:

=A1+(A1-A2)/(B1-B2)*(1-B1)