Enter total units ordered and units shipped for a period to calculate your fill rate. If the number is lower than you'd like, check the reorder point calculator or the stockout cost calculator to see what a higher fill rate is actually worth.
Fill Rate Calculator
Fill rate
93.6%
Share of ordered units shipped immediately from stock on hand.
How to use this number
Calculate fill rate per SKU, not just company-wide. A healthy overall average of 96% can still hide a handful of SKUs stocking out repeatedly — those are the ones actually driving lost sales and customer complaints.
A falling fill rate on a specific SKU is a signal to revisit its reorder point and safety stock, not just to place a rush order. If it keeps happening on the same items, the root cause is usually the buffer being sized for average demand instead of peak demand or a supplier's actual lead time.
Frequently Asked Questions
What is the fill rate formula?
Fill Rate % = (Units Shipped ÷ Units Ordered) × 100. It measures what share of ordered demand you were able to fulfill immediately from available stock, over a given period.
What is a good fill rate?
95%+ is a common target for most retail and distribution businesses. E-commerce operations competing on delivery speed often aim higher (98-99%+), while make-to-order or highly seasonal businesses may accept lower rates for less critical SKUs.
What is the difference between unit fill rate and order fill rate?
Unit fill rate (calculated here) looks at total units shipped versus ordered across all orders. Order fill rate is stricter — it only counts an order as "filled" if every line item shipped complete, so a single missing unit fails the whole order.
Does this calculator save my numbers?
No. This is a client-side calculation only — nothing is sent to a server or saved. Refreshing the page resets it to the defaults.
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