EOQ tells you how big to order; this tool tells you how often. For perishable goods, slow-moving SKUs, and items with strict MOQs, ordering frequency is a trade-off between ordering cost, carrying cost, and shelf life. This calculator finds the balance, and also flags when the math breaks — for example, when MOQ forces a much larger order than the cost optimum.
Order frequency (how many POs per year) is the inverse of EOQ: f = D / Q. Most operators use it loosely — "we order monthly" — but the right number depends on four things at once:
The first three give you an economic optimum. The fourth often forces you away from it. This tool computes both and shows you whether the constraint binding.
If shelf life binds (Q > D × shelf_life / 365), reduce Q to match shelf life — accepting the higher per-order cost — or negotiate with the supplier for shorter production runs.
If MOQ binds (MOQ > economic Q), either accept the larger order and the higher carrying cost, or look for a different supplier. To see how much the constraint costs you, this tool reports the gap in $ per year.
If both bind, the SKU is a poor fit for the supplier. Consider drop-shipping, a different form factor, or stockless program.