Work Tools

Fill Rate Calculator

Estimate fill rate from requested units and fulfilled units and show how many units were not filled.

Updated April 12, 2026
Free online tool
Planning and research use

Why this page exists

Service levels are easier to discuss when requested units and fulfilled units turn into one clear fill-rate percentage instead of two separate totals. This calculator helps visitors estimate a simple fill rate and shows the units that were not filled so the service gap is easier to understand.

Interactive tool

Run the estimate

Enter your numbers and read the result first, then use the sections below to understand what affects the outcome.

Calculator

Fill rate calculator

Estimate order or inventory fill rate from requested units and fulfilled units.

Result

95.00%

Estimated fill rate based on fulfilled units divided by requested units.

Fill rate95.00%

Units not filled60

Units requested1,200

Units fulfilled1,140

1,140 fulfilled units out of 1,200 requested units gives a fill rate near 95.00%.
60 requested units were not filled in this simple estimate.
Use this as a basic service-level snapshot only, because some teams measure fill rate by order line, first shipment, or other service definitions.

This is a basic service-level estimate. Teams can define fill rate differently depending on whether they track lines, units, orders, or first-shipment performance.

Planning note

Last updated April 12, 2026. Use this tool to compare scenarios and plan ahead, then confirm important details with the lender, employer, insurer, contractor, or other qualified provider involved in the final decision.

How it works

What the calculator is doing

Enter the units requested and the units fulfilled or shipped.

The calculator divides fulfilled units by requested units to estimate fill rate.

It also shows how many units were not filled in this simple service-level view.

Understanding your result

This is a basic fill-rate estimate, not a full operations dashboard metric. Some teams track fill rate by unit, line, order, or first shipment, which can change the result meaningfully.

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Examples

Ways people use this tool

Example scenarios help turn a quick estimate into a more useful comparison or planning step.

Check service levels for a single period

A quick fill-rate estimate can make it easier to summarize whether demand was met without building a full report.

Compare two fulfillment periods

Using the same simple metric across periods can show whether supply performance is improving or slipping.

Pair fill rate with reorder and safety-stock planning

Inventory planning metrics become more useful when service performance is easy to read at the same time.

FAQ

Common questions

How is fill rate calculated?

The calculator divides fulfilled units by requested units and multiplies by 100 to show the result as a percentage.

What are units not filled?

They are the requested units that were not fulfilled in this simple estimate, calculated as requested units minus fulfilled units.

Can teams define fill rate differently?

Yes. Some teams measure by units, order lines, complete orders, or first shipment, so this tool should be used as a quick planning metric rather than a universal operational definition.

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Keep comparing

Use these related tools to compare nearby scenarios, check a second estimate, or keep narrowing down the right decision.

Work ToolsUpdated April 12, 2026