Fulfilment metrics
Backorder rate calculator.
See what share of your orders, order lines or units could not ship from stock.
Backorder rate = backordered / total x 100, counted in the same unit (orders, lines or units).
Your numbers
Result
Worked example
36 of 1,200 orders were placed on backorder in a month: 36 / 1,200 x 100 = 3.0%. The other 97.0% shipped from stock. Counted by units instead of orders the same month might read very differently, so keep the unit constant.
How it works
A backorder is an order for an out-of-stock item that is awaiting fulfilment (Wikipedia, Backorder). The rate is the share of the total that ended up backordered: backordered divided by total, times 100.
The page does not claim an official universal definition; companies count by orders, order lines or units, and the choice changes the number. Pick one, state it, and use the same one every period. For a unit-based view of how much of what was ordered you filled, use the order fill rate calculator.
Count orders received in the period for the denominator and orders that could not ship from stock on first allocation for the numerator. Orders that ship partially need a rule: count them as backordered, or measure by lines or units.
Sources (opened 2026-10-18): Backorder - Wikipedia. The formula wording above follows these pages; the example figures and all arithmetic are ours.
Inputs are user-entered figures. Results are planning estimates, not financial advice or a forecast. Everything runs in your browser. Nothing you type is sent or stored.
FAQ
How do you calculate backorder rate?
Divide the number of backordered orders by total orders and multiply by 100. 36 of 1,200 is 3.0%.
Should I count orders, lines or units?
Any of the three works if you stay consistent. Units show how much demand went unfilled, orders show how many customers waited.
Is backorder rate the opposite of fill rate?
When both are counted the same way, the in-stock share is 100% minus the backorder rate. Fill rate is often counted in units, so check the basis before comparing.
What is a good backorder rate?
This page does not publish benchmarks. Lower is better for customer experience, but zero can mean you hold more stock than needed. Track it against your carrying cost.