What level of granularity are you using in your estimates? Are you just calculating a number for the whole (eg "I think that will take 120 hours") or are you al

What level of granularity are you using in your estimates? Are you just calculating a number for the whole (eg "I think that will take 120 hours") or are you also breaking that down as much as possible? I've found that if I can get an estimate broken down into tasks of <10 hrs/ea then it actually turns out to be pretty close. That being said, the larger the project is, the greater the probability of underestimatitis. As soon as you hit 250+ hours, I've found estimates to become increasingly less accurate.