How soon do babies walk after standing?

So my baby started crawling at 5 months. A week before he turned 6 months he started to stand alone leaning on couches, big teddy bears, tables, anything their is , he will stand on it. He is obsessed with standing, even when he's tired he will stand and cry. Problem is every once in a while he tries to stand on his own and falls and hurts his head by falling so hard, (carpet floors) should I get a helmet ? He's literally standing every second so it's hard to cetch him every time. And even if he falls , and cried from the pain, he will get right back up and do it again. He is to fearless. It's scary. But how soon do you think he will be walking? He is already been standing for a little over a week now. And is getting much better at it every day.