I was going to say "also, isn't the Swedish word for 'quick' snabb?" But then Wiktionary told me that there is, in fact, also a word kvick with a similar meaning.
Extra bonus: it turns out that quick/kvick is cognate with Italian/Spanish/Portuguese vivo 'alive' (which makes the older sense in "the quick and the dead" make more sense, too!).
There is "kvick", sure. But "kalkul" certainly isn't a word. The closest match would be "kalkyl". So the language seems to be named by messing up the spelling of two words, which I guess isn't impossible but still somewhat ... weird.
Extra bonus: it turns out that quick/kvick is cognate with Italian/Spanish/Portuguese vivo 'alive' (which makes the older sense in "the quick and the dead" make more sense, too!).