The number of mold cavities defaults to 1. The user can override the default and specify the number (1-256)—see Additional User Inputs.

The user can also direct aPriori to calculate the number of cavities in the cavity layout with the smallest perimeter that can accommodate the number of cavities required to produce the required annual volume (specified by the user in the Cost Guide).

Calculation of the required number of cavities assumes round-the-clock production and depends on the following:

The layout with the smallest perimeter that can accommodate the required number of mold cavities is determined as follows. From the table below, aPriori selects the rows whose value for Number of Cavities is greater than or equal to the required number of cavities. From these rows, aPriori selects the row whose values for Cavities Length Wise and Cavities Width Wise result in the smallest semiperimeter, calculated as follows:

This calculation ignores mold borders and gaps between cavities.

(Note: the column Num Cavities Multiplier is reserved for future use.)