Fill Rate Calculator
Calculate Fill Rate step by step: units shipped from stock on first attempt ÷ units ordered.
In short
Formula: Fill rate = units shipped from stock on first attempt ÷ units ordered.
What this calculator does
Calculate Fill Rate step by step: units shipped from stock on first attempt ÷ units ordered. Worked example, questions and limitations included.
Use it to turn Units shipped from stock on first attempt, Units ordered into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this inventory calculation.
Inputs and what they mean
- Units shipped from stock on first attempt
- — number value.
- Units ordered
- — number value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Unit fill rate as defined in the ASCM dictionary.
Line and order fill rates use the same ratio with lines or orders instead of units.
Measures demand met from stock, unlike cycle service level.
Fill rate = units shipped from stock on first attempt ÷ units ordered.
Inputs used: Units shipped from stock on first attempt, Units ordered.
Worked example
Monthly fill
- 9,600 ÷ 10,000 = 96%.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- One period.
- Definitions of 'first attempt' vary.
- Ignores substitutions.
- Results are planning estimates built only from the figures you enter. No prices, rates, demand patterns or service levels are built in, and the results are not supplier quotes or carrier rates.
- The result depends on the values you enter for this fill rate calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Common questions
Unit, line or order fill rate?
Enter lines or orders instead of units to get those versions. Order fill rate is usually the strictest.
Do late shipments count?
Normally no — only what was filled from stock on the first attempt. Check the formula, example, and limitations on this page before using the result for a real inventory decision.
Is this the same as service level?
No. See the service level calculator for cycle service level.
How do I use the Fill Rate Calculator?
Enter the required values for Units shipped from stock on first attempt, Units ordered. The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Fill Rate Calculator use?
Fill rate = units shipped from stock on first attempt ÷ units ordered. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Fill Rate Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
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