Fill rate formula calculator for units, lines and orders
Compare three fill rates from the same orders: units shipped, lines filled in full and orders shipped complete, each with its formula and the decisions it suits.
A supplier can send 95 percent of the units you ordered and still leave something missing from one order in four. This free fill rate calculator works out three rates from the same orders: units shipped, order lines filled in full and orders shipped complete. Each result shows its formula, so you can see where the shortfall appears.
Use it for a supplier's deliveries against your purchase orders, or for your own shipments to customers. The calculation uses only the numbers you type, and nothing you enter is saved.
How to use the calculator
- Choose the orders to measure, such as every purchase order one supplier delivered last quarter. All six numbers must come from those orders.
- Enter Units ordered and Units shipped, up to the quantity ordered. If a line arrived with extra, count only the quantity ordered, so a spare case of one product does not hide a shortage of another.
- Enter Order lines, one for each product on each order, and Order lines filled in full. A partly filled line does not count as filled.
- Enter Orders and Orders shipped complete, the orders with every line filled in full.
- Select Calculate, or Use example to load the sample figures.
Units can be decimals, for stock sold by weight; lines and orders are whole numbers. The calculator checks that the counts agree: nothing filled can exceed what was ordered, there are at least as many lines as orders, and each incomplete order needs at least one short line.
Three rates, three formulas
Unit fill rate = units shipped ÷ units ordered × 100
Line fill rate = order lines filled in full ÷ order lines × 100
Order fill rate = orders shipped complete ÷ orders × 100
One missing unit barely moves the unit rate, but it makes its whole line count as not filled and its whole order as incomplete. That is why the line rate often sits below the unit rate, and the order rate below both.
Definitions vary. The AHRMM worksheet for hospital supply teams divides lines filled in full by lines ordered and leaves partly filled lines out, the rule this calculator uses for lines. Some businesses count only the first delivery; others count backorders that arrive later. Pick one rule, write it down and keep it, so each quarter compares with the last.
Worked example: one supplier's quarter
A fictional shop placed 20 purchase orders with one supplier over a quarter. This fill rate example uses the figures that Use example loads:
| Input or result | Value |
|---|---|
| Units ordered | 2,000 |
| Units shipped, up to the quantity ordered | 1,900 |
| Order lines | 160 |
| Order lines filled in full | 144 |
| Orders | 20 |
| Orders shipped complete | 15 |
| Unit fill rate | 95% |
| Line fill rate | 90% |
| Orders shipped complete, as a rate | 75% |
1,900 ÷ 2,000 × 100 = 95%, 144 ÷ 160 × 100 = 90%, and 15 ÷ 20 × 100 gives an order rate of 75%. The 100 missing units were spread over 16 lines on five orders, so one order in four arrived with something missing.
Which rate suits which decision
- Unit rate: how much stock arrived. Use it to plan stock cover. If a supplier regularly sends 95 percent of the units, the shortfall eats into the buffer from the safety stock calculator, and your reorder point may need to come earlier.
- Line rate: how many products went short. Each short line can leave a gap on the shelf or a line on a pick list that cannot be picked. Use it to find products to watch or to buy from a second source.
- Order rate: how often an order arrived whole. It matters most when an order is only useful complete, such as a customer's order or stock for a promotion. A supplier fill rate measured this way is a fair criterion in the supplier comparison scorecard, if every supplier is measured the same way.
If short lines keep leaving empty shelves, see how to prevent stockouts.
Frequently asked questions
Can I calculate fill rates without an account?
Yes. Enter the figures and calculate. Nothing is saved or sent, so use Copy result to keep the rates and steps.
How to calculate fill rate by hand?
Pick one level: units, lines or orders. Divide what was filled in full at that level by what was ordered, then multiply by 100. With the sample orders, 144 ÷ 160 × 100 = 90% of lines.
What is a good fill rate?
There is no single benchmark, because businesses count it in different ways. The AHRMM worksheet above suggests hospital stockrooms aim to fill 93 to 98 percent of lines. Compare your own rates over time, for the same supplier and definition, rather than with another business's figure.
Fill rate vs service level: what is the difference?
The NC State reorder point tutorial separates them. Cycle service level is about meeting demand during the reorder cycle, while you wait for a delivery. Fill rate is the percent of demand met from stock across all periods, so it is usually higher.
Is case fill rate the same as unit fill rate?
It uses the same formula with cases in place of units. Enter cases ordered and cases shipped in the two unit fields, and do not mix cases and single units in one calculation.
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