De or het routeberekening?

The correct Dutch article is:

de routeberekening

Rule Words ending in -ing: almost always de. See the rule

How to use routeberekening

the routeberekeningde routeberekening
this routeberekeningdeze routeberekening
that routeberekeningdie routeberekening
our routeberekeningonze routeberekening
your routeberekeningjouw routeberekening
every routeberekeningelke routeberekening
which routeberekening?welke routeberekening?
a big routeberekening / the big routeberekeningeen grote routeberekening, de grote routeberekening