How do you become good at estimating? Because I’m terrible at it

Whether it’s height, weight, or time, I always underestimate. How long will it take me to drive to Newton Centre? 25 minutes would become an hour. How long will it take me to finish a project? 5 days would turn into 3 weeks. Even when I think I overestimate, I still underestimate.

I think estimation is a function of experience. The more experience I have with software projects and schedules, the better I’ll become. However, the one thing I think continues to ring true is: Always overestimate. And once you come up with another estimate, overestimate again

Underestimating is bad. Overestimating isn’t as bad.