I'm confused as to what to use in order to calculate the equity or percentage to be correct in split spots

The method I use is

Ex: Villian bets $5 into $10 pot

Hero needs to call $5 to win $10. Because total pot is $20 including Hero's bet and then chopped in half .

But looking at Split Suit Article. He gets a different answer when using a pot odds method

He saids to split the pot (excluding hero's bet) , which gets $7.5 to $5 or 1.5:1 which is 40%.

https://www.thepokerbank.com/articles/strategy/split-pot-math/