estimating the capacity for my TimeMachine drive

[zoran]

I want to buy a drive to work as my TimeMachine backup drive. How big should it be, if my data is 1TB? Is there some "% rule of thumb" that i must follow in orderestimate what it should be?

 

[Weaselboy]

Most recommend 1.5 to 2X the amount of data you think you will ever need to backup. This gives you plenty of space for Time Machine to keeps versions of files for you.