I will get the sail out and measure it later today.
This is the Wiki on the Hunter 216 if you don’t have it.
en.m.wikipedia.org
The Wiki lists a bunch of info including the sail area of the jib at 80sq ft. I have no idea if that is accurate as I have very little experience in how to measure and then calculate the area of a sail as as
@DrJudyB indicated (from vast experience BTW) it’s not just simple math.
The jib on the 216 has the forestay integrated into it and the cleats to manage it are not adjustable so I don’t know if you have a lot of options for new other than material choice and I guess panel layout. I have found that most of the power on this boat comes from the big mainsail.
You mention you have put your bait away so I just want to ensure you are aware of the need to remove the Sailtec hydraulic centreboard lift and then store the unit upright.