You don't say what your gain is. Your gain is the difference between your cost basis and the selling price. Cost basis is what you originally paid, plus the cost of any permanent investments you made in the land (such as installing utility connections). You can also include certain legal fees that might be required when you purchased the land. See basis of assets,
https://www.irs.gov/taxtopics/tc703
If the land was a gift or inherited, your basis is more complicated to figure out.
Then, federal capital gains tax rates are 15% or 20%, depending on your other income. The capital gain could be subject to an additional 3.9% net investment tax, depending on your other income. I will take the other expert's word for the NC state income tax.
