How Much Dry Pasta to Use per Person

We cook a lot of pasta so of course I wondered how much dry pasta one is to use per person. If you look at different Italian or German sites they recommend 100-125g of dry pasta per person. That is about 4oz per person. On US sites I found that they usually say 2oz per person. I think that is strange. When I buy spaghetti for example I buy it in 500g packs (roughly 1lb) and that works for 4 people with a little bit of leftover. So in my experince 100-125g per person is correct. If one converts grams into ounces you get approx. 4oz = 113,5g. Seems like the perfect amount to me. For pasta salads 3-3 1/2oz per person is enough.