Most chips aren’t made from potatoes. The manufacturers use flour (wheat or corn) and a mixture of starches. As a rule, the chip dough contains not more than 42% of potatoes. A bright and "natural" taste is achieved with the help of flavor additives.
There are other producers who use real potatoes. A large pack contains about 2 average potatoes. It’s important to know that such a product is subject to a larger tax, which means that real potato chips won’t come cheap.