About 1 liter of helium per gram of lift. To his credit, he says that right at the start, so it’s not clickbait. Anyway, I’d be remiss if I let this popular video go unmentioned here. We just found out about the Aéroplume in France which lets visitors strap into giant balloons and fly them around inside a WW1 giant airship hangar. It’s entirely powered by the user rowing themselves around with big wings like a kayak. Very simple, but I really want to own one of these someday.
Source: Tom Scott via YouTube subscription and /r/MealtimeVideos