Unit fill rate
Inputs: 12,000 units requested and 11,400 shipped.
11,400 ÷ 12,000 × 100 = 95.00%. The 600-unit shortfall is 5.00%, which meets a 95% target exactly.
Fill Rate Calculator: Unit, Order, Line & Backorder Fill Rate
Fill rate is the percentage of requested demand filled on the first pass: shipped ÷ requested × 100.
Use this fill rate calculator for unit, order, line, case, warehouse, vendor, or backorder-based fill rate, with target gaps and step-by-step substitution.
Inputs
Measures requested units filled from available inventory.
Total demand requested before cancellations or substitutions.
Quantity filled on the first shipment.
Unfilled quantity carried to backorder.
Use 95%, 97%, or 99% benchmarks, or enter your own target.
Results
Fill rate:—
Unfilled count:—
Shortfall:—
Requested total:—
Target status:—
Service label:—
Enter requested and shipped values to see the substitution.
Benchmark target
Gap to target:—
Needed to hit target:—
Advertisement
Multi-line scenario
| Row label | Requested | Shipped | Backordered | Fill rate | Action |
|---|---|---|---|---|---|
| — | |||||
| — | |||||
| — |
Weighted fill rate:—
Total unfilled:—
Lowest row:—
Calculation notes
Assumptions: Fill rate measures first-pass fulfillment. Requested quantity must be greater than zero. Partial shipments count only for the amount shipped. Backorders represent demand not filled on the first pass.
When the backorder formula is enabled, the filled count is derived as requested minus backordered. If shipped is greater than requested, the calculator caps the fill rate at 100% for the result and flags the over-shipment so you can review the source data.
Calculations run locally in your browser and are not sent to Starlight Tools.
Fill rate explained
Definition
Fill rate measures how much requested demand was filled immediately. It is commonly used in logistics, ecommerce, wholesale distribution, manufacturing supply, warehouse operations, and vendor scorecards.
Formula
Standard fill rate: Shipped ÷ Requested × 100
Backorder fill rate: (Requested - Backordered) ÷ Requested × 100
Fill-rate types
Unit fill rate
Requested units filled. Best for SKU availability and inventory planning.
Order fill rate
Complete orders filled without shortfall. Best for ecommerce and customer service.
Line fill rate
Order lines filled completely. Best when each line item matters operationally.
Case fill rate
Requested cases filled. Best for wholesale, pallet, and case-pack operations.
Warehouse fill rate
Warehouse requests filled from available stock. Best for site or DC comparison.
Vendor fill rate
Purchase or replenishment requests filled by a supplier. Best for vendor performance reviews.
Good fill-rate targets
Targets depend on margin, lead time, demand volatility, and customer promise. Many teams use 95% as a minimum service threshold, 97% as a strong operating target, and 99% for critical or high-priority items.
Common causes of low fill rate
Low fill rate is often caused by inaccurate forecasts, late suppliers, reorder points set too low, insufficient safety stock, allocation rules that favor one channel, warehouse picking errors, master-data errors, or demand spikes that exceed the planning model.
How to improve fill rate
Review reorder points, safety stock, supplier reliability, forecast error, allocation logic, substitution policy, cycle count accuracy, and order-picking accuracy. Segment targets by SKU class so critical items receive higher service buffers than slow-moving items.
Examples
Order fill rate
Inputs: 2,000 orders requested and 1,930 complete orders shipped.
1,930 ÷ 2,000 × 100 = 96.50%. This is below a 97% target by 0.50 percentage points.
Line fill rate
Inputs: 8,500 order lines requested and 8,245 lines filled.
8,245 ÷ 8,500 × 100 = 97.00%. Line-level service is on target if the benchmark is 97%.
Backorder-based fill rate
Inputs: 4,000 cases requested and 260 cases backordered.
(4,000 - 260) ÷ 4,000 × 100 = 93.50%. The backorder volume points to a 6.50% unfilled share.
FAQs
What is fill rate?
Fill rate is the percentage of requested units, orders, lines, cases, warehouse requests, or vendor requests filled on the first pass.
What is the fill rate formula?
The standard formula is shipped ÷ requested × 100. With backorders, use (requested - backordered) ÷ requested × 100.
What is the difference between unit fill rate and order fill rate?
Unit fill rate measures quantity filled, while order fill rate measures complete customer orders filled without shortfall.
What is line fill rate?
Line fill rate measures the share of order lines filled completely on the first shipment.
Is fill rate the same as service level?
Fill rate is one service-level metric. Service level may also refer to availability, cycle service level, or customer promise performance.
How is fill rate different from OTIF?
Fill rate measures how much was filled. OTIF measures whether the order was delivered on time and in full.
How is fill rate different from perfect order rate?
Perfect order rate is broader because it usually includes completeness, on-time delivery, damage-free delivery, and documentation accuracy.
Can fill rate exceed 100%?
Operational fill rate should normally be capped at 100%. If shipped exceeds requested, review over-shipments or data quality.
How should cancellations affect fill rate?
Use a consistent policy. If cancellations represent unmet demand, keep them in requested quantity; if they are customer-requested before fulfillment, many teams exclude them.
How often should fill rate be measured?
Measure at the cadence used for replenishment and service review, commonly weekly for operational control and monthly for management reporting.
How can I improve a low fill rate?
Improve reorder points, safety stock, supplier reliability, forecast accuracy, allocation rules, warehouse accuracy, and master-data quality.
Is this calculator private?
Yes. All calculations run locally in your browser.