How hard do you have to hit to break someones rib?

Answer 1

You don't have to hit that hard at all. Ribs are fairly fragile, but it also depends on which rib and where you hit the rib. The bottom ribs are obviously easier to break than the top ribs.

I broke my older sisters ribs when I was 12 years old( I'm the younger sister, not brother). That was before I had any Martial Arts training. Now that I know how, I try to avoid hitting people. You can do a surprising amount of damage to another person with just your hands.

Peoples ribs are broken all the time just doing CPR. And that's pressure not impact.