My 11-week old currently has no schedule as she still seems to sleep so much of the time. I can always count her to sleep from 11-12 at night until 6-7 in the morning. This is somewhat unusual for her age, but for whatever reason, it is natural for her. After that her sleep is frequent and random. It's easier for me to say that she is awake and alert for about 4-5 hours each day, but not at consistent times.
When my son was a baby, he slept much, much less. He may have taken two naps a day at that age. In addition to those two 1-2 hour naps, he probably took 3-5 five to ten minute naps as well. Total, I don't think he slept more than 14-15 hours each day even though a baby that age should get around 16 hours of sleep.