SmartAsset and Yahoo Finance LLC may earn commission or revenue through links in the content below. I am selling my house and the price is $504,999. After paying off this house I will net $400,000. Do I have to pay a capital gains tax as I’m planning to pay off my retirement home with the money I netted? – Thomas The answer is solidly “it depends,” both in terms of whether you’ll have to pay capital gains tax and how much you might have to pay. Let’s talk about the rules around this situation first, an ...