The Calculus mission no longer shows up in the Subjects menu with a percentage for the work completed.
To get a glimpse of your progress, go to https://www.khanacademy.org/math/calculus-home or to the individual calculus missions and check it out. You won't see the total Calculus, though.
This issue on the to-do-list, but unfortunately we don't have a date for when the functionality will be back. We apologize for the inconvenience.
Internal ticket: 236094653402012
Jan. 4th 2017