Normal household carpet. NOT industrial carpet. Per square foot.
it varies..depends on the quality of the carpet...use google !
The average price for carpet will depend on a few things. The type of yarn, the amount of yarn and type of store you buy it from. Unless you are comparing apples to apples it is not possible to get a fair average price. I have a carpet business and customers ask a question like this all the time. So this is what I tell them. My company has a 25 ounce carpet with a FHA padding for $6.99 per square yard. Just over 77 cents a square foot. This carpet is not industrial and is better then rental carpeting. And the price goes up from this point. You must tell the store you are call the exact type of carpet you want to get comparison prices, that way you are apples to apples, not whatever store one gives you compared to store two. Installation cost run around 30 cents per square foot in my area (depending on size of job, type of carpet, stairs etc.)