Does twitch deduct a lot of MB?

I'm in the hospital and I don't have Wi-Fi here. But I still have 7 gb flat rate.

I want to watch it on twitch stream but I don't really know if a lot of MBits is deducted. How much do you think mb per minute is it deducted?

Depends on what settings you have. But it pulls a lot.

480p?

Too much. That might be enough for just under an hour.