The calculator is the last step, not the first move. Four steps of thinking, one tool, then two of judgment.
Heaviest carton at its shortest length is the worst case.
Worst-case carton sets it. Round up to catalog, never down.
Design inclines to the minimum in the mix, with margin.
Leading dimension over three. The one people trust without looking.
When the calculator changes: the Product Spec Calc is the authority for conventional conveyor. Goods-to-person systems and ASRS come with their own sizing tools. Identify the platform early, get the manufacturer's tool, and never substitute a general calculator for a manufacturer-specific one.