Generally speaking, if you're selling land for more than you paid for it, you will pay federal taxes on the amount of capital gains. Most people selling land will have owned it for two or more years, so the long-term capital gains tax rate would apply, which is between 0-20% depending on your income bracket. Depending on where you live, some states also tax capital gains. For a list of states that tax capital gains, visit taxfoundation.com