how much does internet does it use?

how much internet does playing any xbox game online take up?
like for example how much MB would say 1 full game of team deathmatch on mw2 use of my internet usage?

i'd just like to know cos i think my internet usage is getting pretty low and its not even halfway through the month yet :(

sorry if i posted in wrong section or sumfin but i couldnt be bothered searchin through other forums when i use this one a fait bit.