reckon
/ˈre-kən/
verb
count
estimate, compute
to determine by reference to a fixed basis
reckon the days till Christmas
reckon the height of a building
phrasal verb
to expect (something) to happen : to plan on (something)
The train was an hour late, which was something we hadn't reckoned on.
phrasal verb
to calculate the total number or amount of (something)
He reckoned up the bill.