The average number of pennies that will fit into a 5-gallon jug ranges between 20,000 to 30,000 pennies. The actual number depends on the shape of the jug and when it is considered full.
The most accurate way to determine how many pennies fit in a 5-gallon water jug is to perform the experiment. Reports from individuals who have filled 5-gallon jugs with pennies include the dollar amount the jug held; the total number of pennies can then be calculated based on the dollar amount of pennies in the jar.
The shape of the jug as well as how the pennies are placed within it can affect how many will fit. Adding pennies to the top of the neck of the jug versus filling to the bottom of the neck of the jug is also a consideration.