How much will I get charged if I over-use data on Wi-Fi instead of mobile?

So, I love to watch youtube on my phone or netflix at night to keep me occupied until I get a little sleepy. Since I know full well that using youtube or netflix on mobile will increase data usage by a large amount especially on cellular/mobile data. But what about on Wi-Fi data? Will my verizon bill still skyrocket from Wi-Fi data usage or is it connected to my internet bill for my home. A little confused on how exactly Wi-Fi usage gets billed on phones like android or Iphone.

If you're connected to your home Wi-Fi, then the data counts against your home Wi-Fi.

If you're using LTE then it counts against your cellular usage.

Verizon fios doesn't have a limit on how much Wi-Fi you can use. According to the Fios website, I used almost 200 gb last month which doesn't sound right. By whatever.

Xfinity has a soft cap of 250 gb but it doesn't really enforce it unless you go way over the limit for several months then you'll get a call giving you suggestions on how you can reduce your Wi-Fi usage.