Calculating yardage

I have some old jeans that I want to make into body of jacket and then knit the sleeves and collar…or perhaps hood. Most likely would use something like Peaches & Creme for more of the ‘faded denim’ effect. How best to determine the yardage needed for just the sleeves and collar? I recall a previous sweater needing roughly 2 balls for a hood. I’m thinking each sleeve would be about 1.5-2 balls. Sound about right?