Substituting yarns for gauge

I want to knit my husband a sweater, he picked a nice one by picture, but it requires Organic Wool using size 9 needles and a gauge of 17sts and 23 rows= 4". okay, here’s the problem, my husband HATES wool. What yarn do I substitute with theses dimensions. It requires 5 skeins for a Large, how many skeins would I need?
Thank you for any advice at all

I’d start looking here: to find a yarn that has a similar guage. It may recommend a different needle size (but will probably be between 7 - 10), but you mostly want to match the stitches per inch.

As to how many you need to buy - you need to look at the original yarn suggested. Say it it coems in 500 yd sken and they want you to get 5 - you need 500 x 5 = 2,500 yards. Now look at the yarn you decide to use - say that comes in skeins of 650 yards. So take the total 2,500 yards, divided by 650 = 3.85 or 4 skeins.

What about superwash wool? He won’t itch or even know it’s wool if you don’t tell him. It’s also cooler (temperature, I mean) than synthetics.

I wouldn’t try to sell him on wool, or spend the money to try and ‘fool’ him. Just try an acrylic, cotton/acrylic blend or something else in a worsted weight. And you want to total the yardage in the 5 skeins called for in the pattern and get the same amount in your substitute.

Thank you so much. I’m not any good with the conversions. You have no idea how much I appreciate this.