First of all, management shouldn't be estimating how long it should take you to do something, they should be asking you for estimates. I don't have productive

First of all, management shouldn't be estimating how long it should take you to do something, they should be asking you for estimates. I don't have productive advice on how to deal with this other than suggesting this to management and maybe looking for other work if they disagree. Second, your estimates will still be wrong (almost always on the underestimating side) and sometimes wildly so, thanks to Hofstadter's Law (It always takes longer than you expect, even when you take into account Hofstadter's Law, see: http://en.wikipedia.org/wiki/Hofstadter's_law http://en.wikipedia.org/wiki/Hofstadter's_law). Third, you will get better at estimating the time of your own tasks with time and lots of experience, but you still have to accept that estimation when it comes to software is more of a black art than a science.