Fill Rate Calculator
Enter the orders you received and the orders you shipped complete, and this calculator returns your order fill rate as a percentage: the share of demand you met from stock, first time, with no backorder. It is the simplest honest score a warehouse or online store can keep on itself.
The tool checks the two counts against each other, nothing else. What counts as “fulfilled” is your definition to apply consistently: complete, from stock, first attempt is the standard reading used here.
Quick Answer
Fill rate = (orders fulfilled complete ÷ total orders) × 100. Ship 460 of 500 orders complete, the worked example pre-filled above, and the fill rate is 92.00 %, with 40 orders that did not go out whole. Anything at or above 97 % is excellent going; below 90 %, customers are meeting your stock problems personally.
Key takeaways
- Fill rate counts orders, not effort. An order shipped one item short counts the same as an order that never left: not filled.
- The same two-field tool also produces line fill rate and unit fill rate, if you feed it line counts or unit counts instead of order counts. The label on the answer changes with what you counted.
- A high fill rate bought by carrying mountains of stock is not a win. Read it next to inventory cost, never on its own.
- Track it on a fixed rhythm, weekly or monthly, with the same definition every time. A fill rate that changes definition between periods tells you nothing.
- Quick Answer
- How to use the fill rate calculator
- The fill rate formula, and what "fulfilled" has to mean
- Worked example: 460 out of 500, and where the 40 went
- Order, line and unit fill rate: three numbers, one tool
- What counts as a good fill rate
- What a falling fill rate is usually telling you
- What competing calculators miss
- Frequently asked questions
- Add This Calculator to Your Website
- References
How to use the fill rate calculator
Enter two counts from the same period, click Calculate, and read the percentage together with the unfilled count and the band under it. The results stay hidden until you calculate.
- Total customer orders: every order received in the period, filled or not. Cancelled-before-picking orders are a judgement call; decide once, write it down, and apply it every period.
- Orders successfully fulfilled: orders shipped complete from stock on the first attempt. Part-shipped orders and backordered orders stay out of this number even if they were completed later.
- Check the answer against the guard rails: the tool answers "Please enter valid numbers." if the total is zero or negative, if fulfilled orders are negative, or if fulfilled orders exceed the total. A fill rate above 100 % is a counting error, and the tool refuses to print one.
Two behaviours to know about. Leave a field blank (or type text into it) and the tool returns "NaN %": its checks compare numbers, an empty field produces no number to check, and the division runs anyway. And because the fields accept decimal values, the tool will happily compute a rate from 200.5 orders. Orders come in whole numbers, so if your answer rests on a fraction of an order, the counts feeding it need a second look. Neither quirk changes a properly formed calculation, but both are worth knowing before you quote the figure in a meeting.
The fill rate formula, and what "fulfilled" has to mean
Fill rate = (orders fulfilled ÷ total orders) × 100. That is the whole formula, and its simplicity is why definitions do all the real work.
Worked: (460 ÷ 500) × 100 = 0.92 × 100 = 92.00 %
The standard reading, the one used by the Institute for Supply Management in its Monthly Metric explainer on fill rate, is orders shipped complete from stock on hand, first attempt, without a stockout or backorder. Operations glossaries put it the same way: fill rate is the fraction of demand satisfied immediately from inventory. The moment you let "eventually shipped" into the numerator, the metric stops measuring stock availability and starts measuring patience. Keep the definition strict and the number stays useful: it tells you how often the shelf, the forecast and the picking operation all did their jobs at the same moment.
Worked example: 460 out of 500, and where the 40 went
A store receives 500 orders in a week and ships 460 of them complete from stock. Forty orders hit a problem: a size out of stock, a two-item order with one item missing, a supplier delivery that landed a day late. The fill rate is (460 ÷ 500) × 100 = 92.00 %, which is exactly the calculation pre-filled in the tool above.
Read the 40, not just the percentage. Forty incomplete orders in a week is eight conversations a day with a customer who paid and did not get what they ordered. Some will wait on a backorder, some will cancel, a few will not come back. The percentage tells you the scale; the unfilled count, which the tool prints beside the rate, tells you the workload and the exposure. Both numbers come from the same two inputs, and quoting one without the other hides half the story.
Order, line and unit fill rate: three numbers, one tool
"Fill rate" names a family, not a single metric, and mixing the members up is the most common reporting error in this corner of operations. The Institute for Supply Management draws the same split, between a customer-facing order measure and a unit-by-unit volume measure used for inventory planning.
| Measure | Counts | How strict | Same week, typical result |
|---|---|---|---|
| Order fill rate (this page) | Complete orders ÷ all orders | Strictest: one missing item fails the whole order | 460 ÷ 500 = 92.00 % |
| Line fill rate | Order lines filled complete ÷ all lines | Middle: a two-line order can score one out of two | Say 905 of 950 lines = 95.26 % |
| Unit (volume) fill rate | Units shipped from stock ÷ units ordered | Gentlest: partial shipments still score | Say 1,890 of 1,960 units = 96.43 % |
The worked line and unit figures are illustrative, built on the same week: orders with several lines drag the order rate below the line rate, and a short-shipped unit or two barely dents the unit rate. That ordering, order rate lowest, unit rate highest, is normal, not a contradiction. To get the other two rates from this tool, enter line counts or unit counts in place of order counts. The arithmetic is identical; only the meaning changes, so label the output with what you counted.
Two neighbours are worth separating while we are here. Order accuracy is about shipping the right items without errors, which is a quality measure; an order can be accurate and still unfilled. OTIF (on time, in full) adds the clock to the completeness test. Fill rate asks a narrower question: was it on the shelf when the order arrived?
What counts as a good fill rate
A good fill rate depends on the industry and the promise made to customers, but the bands below are a fair working scale for order fill rate, and they are the same bands the calculator's reading badge uses. Reported healthy ranges in supply chain practice commonly sit between 92 % and 98 %, with consumer retail and eCommerce at the demanding end.
| Order fill rate | Reading | What it usually means |
|---|---|---|
| 97 to 100 % | Excellent | Stock and forecasting are doing their jobs; protect whatever is working. |
| 95 to 96.99 % | Strong | Solid service level; the remaining misses are worth item-by-item review. |
| 90 to 94.99 % | Workable, leaking | The worked example sits here: fine on a slide, felt by customers every day. |
| Below 90 % | Needs attention | One order in ten or more fails; look at forecasting, reorder timing and stock accuracy before anything else. |
Chase the band, not the perfect score. The last two points of fill rate are the most expensive in warehousing, because they are bought with safety stock across every slow line you carry. A business is allowed to decide that 96 % at a sane inventory cost beats 99 % at a ruinous one. What it is not allowed to do, if it wants the metric to mean anything, is quietly loosen the definition of "fulfilled" until the number improves.
What a falling fill rate is usually telling you
A falling fill rate is a symptom with a short list of usual causes: the forecast missed, the reorder went out late, safety stock was too thin for a demand spike, a supplier delivered short or late, or the system said stock existed that was not on the shelf. Work the list in that order before blaming the warehouse team, because most fill rate problems are planning problems wearing a warehouse uniform.
Three companion calculations help pin the cause down. Compare the period against your average daily demand to see whether demand itself moved. Check how long your current stock lasts with the days of supply calculator, since a fill rate problem often shows up there a week earlier. And when you weigh carrying more stock against missing orders, price the miss itself with the cost of understocking calculator: an unfilled order is not free, it is a lost margin plus a backorder handling cost plus a customer who is now shopping around. For online sellers, fulfilment promises also interact with delivery pricing, which the eCommerce shipping calculator covers from the cost side.
What competing calculators miss
The formula is one line, so competitor pages win or lose on everything around it:
- QuickBooks' fill rate calculator (Australia): a clean two-field tool, but its own worked example prints the division backwards, "(200 / 180) x 100 = 90%", when 180 filled of 200 ordered is the calculation that gives 90 %. A reader copying that layout into a spreadsheet builds the error into their reporting.
- Solatatech's fill rate guide: good coverage of fill rate types, undermined by garbled formulas in the text, including a reversed "(Total Number of Customer Orders / Number of Customer Orders Filled)" version and an example that divides units by orders without saying the unit of count changed.
- DCL Corp's fulfilment guide: strong on causes and fixes, and its line versus case fill rate distinction is genuinely useful. It is a guide without a working calculator on the page, so the reader still does the arithmetic elsewhere.
- Supply Chain Analytics and Number Analytics guides: thorough explainers with order and item variants, again with no tool attached, and benchmarks stated without the caution that the last points of fill rate are bought with inventory.
- The gap this page fills: a working tool with the guard rails visible (no rate above 100 %, invalid counts named), the unfilled order count printed beside the percentage, a band reading wired to the same thresholds the article defends, the order/line/unit distinction with a method for computing all three from one tool, and the tool's own quirks, blank fields returning "NaN %" and decimal counts being accepted, stated on the page instead of discovered in a meeting.
Frequently asked questions
Fill rate is a supply chain metric that measures the percentage of customer orders fulfilled complete from available stock, on the first attempt, without a stockout or backorder. If 460 of 500 orders ship whole, the fill rate is 92.00 %.
For order fill rate, 97 % or above is excellent, 95 to 96.99 % is strong, 90 to 94.99 % is workable but leaking orders, and below 90 % needs attention. Reported healthy ranges commonly sit between 92 % and 98 %, with retail and eCommerce at the demanding end.
No. Fill rate is a share of orders received, so 100 % is the ceiling. This calculator refuses the inputs instead: if fulfilled orders exceed total orders, it answers "Please enter valid numbers." because one of the two counts is wrong.
It shows "NaN %". The validity checks compare numbers, and a blank field produces no number, so the checks pass and the division runs on an empty value. Enter both counts and calculate again to get a real rate.
Order fill rate counts whole orders: one missing item fails the order. Line fill rate counts individual order lines, so a two-line order can score one out of two. Enter line counts instead of order counts in this calculator to get a line fill rate, and label it that way.
No. Order accuracy measures whether the right items shipped without errors, a quality question. Fill rate measures whether the order could be filled from stock at all, an availability question. An order can be perfectly accurate and still unfilled, if it ships late off a backorder.
Work the usual causes in order: sharpen demand forecasting, set reorder points that respect supplier lead times, hold safety stock on fast movers, track supplier fill rates, and cycle-count so the stock record matches the shelf. Loosening the definition of "fulfilled" improves the number and nothing else.
Yes, that is vendor fill rate: your purchase orders (or units) the supplier delivered complete and on time, divided by the total you ordered. Use the same calculator with your purchase order counts, and keep the period and the definition fixed so suppliers are compared fairly.
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References
- Institute for Supply Management. The Monthly Metric: Fill Rate. Accessed October 21, 2026.
- Association for Supply Chain Management (ASCM). Quantifying the Effects of Logistics on System Performance. Accessed October 21, 2026.
- Sourcing Industry Group (SIG). Fill Rate. Accessed October 21, 2026.
- AIM Insight. Supply Chain and Operations Management Glossary (F): Fill Rate. Accessed October 21, 2026.
- Rowton's Training. How to Calculate OTIF and Fill Rate. Accessed October 21, 2026.