A person who doesn’t like to do more than required or who will not work later than the dismissal time unless he is paid overtime. Whatever he does is for his own benefit. The interests of others are secondary to his.
Can such a person be described as “calculating”? If not, what is the correct word?
I think “calculating” is a good choice here. “Conniving” is similar, but is a little stronger, maybe describing someone who figures out how to leave before the dismissal time without getting into trouble.
You could also say that the person in question is no fan of the principle of going the extra mile .