The steel wheel, with the hubcap weighs 20.5 pounds, without a tire. Add the weight of your tire to that to get the whole figure. You can see tire weights on
www.tirerack.com. Just look your tire up and click on the link for Specs.
Yeah, it's heavy. I noticed a huge difference in ride and handling (for the better) when I put the Prius wheels on (with the same tires). Those only weigh 14 pounds each. My tires weigh in at 21 pounds each. So I went from 41.5 pounds at each corner to 35 pounds at each corner. That's a reduction of about 15%.