It all depends. Believe me, I try to use as little water as I need. This is fine for short noodles, it's easy to get away with. Try doing it with linguini and you'll have a hot mess on your hands, I know cause I've tried it. The ends of my linguini noodles (or any long pasta) stick together and stay hard. Knowing first hand how small most electric kettles are the OP will need more than one boiling to cover any noodle.