To calculate the sum of something. A noun or pronoun can be used between "tally" and "up." After we tally up all relevant fees and taxes, your final bill comes to $475.50. We'll have to wait until they tally every vote up before we'll know the winner.
tally something up
to add something up. Please tally everything up and tell me the total. Let's tally up everything and ask for donations.
To calculate something, especially by addition: The waiter tallied up our bill at the end of the meal. The election officials tallied the votes up and announced the winner.