I have done Computer Systems engineering and working for a good company. I am interested in doing a masters (not really because I have much interest in theory but because it helps in career advancement.) How do I calculate how a masters will be a good decision and worth the time, money and energy? My goal is to become a Chief Technology Officer in 10 years (I have 3 years of experience right now and 1 year of experience after graduation.)
If your goal is to be a CTO (i.e. more business oriented) then the value of an MBA would be an idea worth considering. Once you reach a certain level of experience, education becomes icing on the cake. So in ten years time, if it came down between you and another candidate for a CTO position, and you had an MBA (or another master's degree), you would more than likely get the job.
You should evaluate:
a) the knowledge you will again doing the master: probably none, usually it is better to spend the time in self-study.
b) the legal rights the master gives you: in some countries, law request some levels or masters for some jobs or actions (in my country, by example, they are mandatory for teaching at high-school).
c) the prestige of the university.
d) the social contacts you will gain during the master: not only other students, good master has a lot of vip speakers.
e) if the masters includes practices (or research) done in external organizations, and if you are interested on these.
What the other answer failed to note that getting to a CTO position after only 10 years of experience is very rare indeed. Yes, there may be occasional persons that are capable of this achievement, but don't expect it to work for you. Seriously, you should reconsider your career goals if your goal is as ambitious as it is currently.
I would expect most CTO's to have master's degree. Some do have doctoral degrees, but it isn't so common that a doctoral degree would be a surefire way to get to the position. Typically, the benefit of a master's degree is worth more than the costs, so go ahead and finish (or start) your master's degree! For doctoral degree, I wouldn't recommend the same unless you are genuinely interested about the subject (I'm a doctoral student, but then again I'm genuinely interested about the subject).
However, what matters most is that you have to do your job very well to get to the CTO position. Write a lot of very good code, and be helpful to others when they ask questions about your code. If you're the person people ask questions from, promotion to a higher position may very well be near.
A CTO is basically a business manager. You won't be writing code. If you want to be CTO for a software company, become strong in Agile, and the SDLC. You should strengthen project management skills. To become a CTO in 10 years is pretty ambitious. You'll be working 16 hours a day every day for the next 10 years to meet that goal, so you won't have time to do a masters.