What did one potato chip say to the othe potato chip?
"Shall we go for a dip?"
Katie Speck Wicks invented the chip in an accident in 1853 and the Saratoga Chip was first made. It wasn't her brother as is often said. Later Herman Lay (of Lay's Potato Chips) popularized the product. The assertions that potato chips were an aphrodisiac his drove his sales. Of course, he didn't actually say that they were but he didn't say otherwise, either.
It is a function of the length of the potato divided by the width of the slice minus any waste (like you don't want the ends). Real world - get the average size of your potatoes and divide by the average chip thickness then pick a multiplier like 0.95~0.97 to err on the conservative side. This would be reasonable to figure out, say, your yield per bushel.