If you own a house for a year and you are going To sell to buy your parents house that is more expensive do you have to pay capital gains tax if the equity going new

@mjlowell1 reinvesting the profit has no bearing on the tax implications - that rule changed back in 1997.

If you sell your home within 2 years of purchasing it and you are doing so for your own convenience, any profit is subject to capital gains tax. 

So it’s a yes that he will have to pay it even though it’s going into another home.  This is all confusing to me 

Yes, that's right. He will have to pay tax on the gain. It doesn't matter what he uses the money for. Using it to buy another home doesn't make any difference.

You can eliminate some of the confusion if you just forget about the rule that was removed from the tax law 26 years ago, and concentrate on what the current rules are.