Safety Stock Calculator

About this calculator

Safety stock is the extra inventory a business holds beyond expected demand to guard against running out when either demand spikes or a supplier's lead time runs long. The classic method compares the worst realistic case to the average case: it multiplies maximum daily usage by maximum lead time, then subtracts average daily usage multiplied by average lead time. The gap between those two figures is the buffer needed to survive the difference between a normal cycle and a bad one.

Retailers, manufacturers, and distributors use this figure to set reorder points and avoid stockouts without tying up excess cash in inventory that just sits on shelves. Too little safety stock means lost sales and unhappy customers when a shipment is delayed; too much ties up working capital and increases holding costs. This calculator takes your maximum and average daily usage along with maximum and average lead times to compute the buffer level that balances those two risks.