Technically, no quantity of graham crackers is needed when a recipe calls for vanilla wafers. But – unfortunately – math if involved if you want to substitute vanilla wafers for graham crackers.

A vanilla wafer weighs 4 grams, so 35 of them weigh 140 grams, or 5 ounces. A whole graham cracker – not a half and not a quarter, even though it is clearly scored to be divided – weighs 16 grams. So a whole packet of them, which is to say 9 graham cracker in the standard plastic wrapper, is 144 grams, or almost exactly what you need.

We chose to weigh the cookies in grams – no relation to grahams – because a single vanilla wafer weighs 0.14109568 ounces and a whole graham cracker weighs 0.56438272 ounces, and that is way out of our league mathematically. For those sticklers among you, 5 ounces is 142 grams, so the vanilla wafers are 2 grams shy of the mark, and the graham crackers are 2 grams over, but we rounded, because we can.