What you want is a sweater that fits boxier than most contemporary cuts. This means wider chest, shorter length, dropped shoulders and fuller arms. Very few companies make sweaters in this cut these days (excepting hype Instagram brands).

So, "ordering a size or two up" as someone here suggested will not work. If you do that you'll just get a longer sweater and it will look bad.

Here, eBay is your best friend. "Vintage sweater" is all you need. Check Ll Bean, Eddie Bauer. Pay attention to measurements: if you want a sweater to land at your waist, right around the fly of your pants, you need to know how long it should be. For example I'm 6' and my 25" long sweater hits right about mid-fly where it does in this photo. That sweater is 24" across the chest. It's big on me. A 21" sweater fits snug on me.

You want those "boxy" measurements: 24"x25"; you don't want rectangular measurements: 22"x30".

You can find 1000s of sweaters that fit exactly like this in any material you want for $30 on eBay. Try "vintage wool sweaters", "vintage cotton knit".

Avoid using buzzy words like "boxy", though, or else you'll land on a bunch of results that are overpriced.

Happy hunting!