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Supplier Lead Time Per-Shipment Cost Estimator

The Supplier Lead Time Per-Shipment Cost Estimator estimates the financing or carrying-cost burden created by inventory that is committed during supplier lead time, then allocates that burden across outbound shipments in a reporting period. It is useful for showing how slower replenishment can translate into a measurable per-shipment inventory cost.

The calculator first estimates average lead-time inventory value from daily purchase value and supplier lead time. It then applies an annual carrying-cost rate for the entered period and divides the result by shipment count. This is a planning allocation, not a supplier invoice amount. Freight charges, duties, purchase price paid to the supplier, and safety-stock costs should be included separately unless they are intentionally part of your chosen carrying-cost methodology.

Lead-time cost allocation inputs

USD/day
days
%
shipments
days
Result
—
Supplier lead-time cost per shipment
Lead-time inventory value—
Carrying cost for period—
Lead-time carrying cost per day—

1. Enter daily replenishment value
Use the average monetary value of goods purchased or committed per day.

2. Set supplier lead time
Enter the elapsed replenishment days represented by the supplier cycle.

3. Enter carrying-cost rate
Use the annual percentage applied to inventory capital and other carrying components in your methodology.

4. Match shipment volume and period
Enter outbound shipments and reporting days from the same operating period.

5. Review per-shipment allocation
Use the result to compare lead-time scenarios while keeping demand value, carrying rate, and shipment volume consistent.

Lead-time inventory value = Average daily replenishment value × Supplier lead time
Annual lead-time carrying cost = Lead-time inventory value × Annual carrying cost rate
Period carrying cost = Annual lead-time carrying cost × Reporting period days ÷ 365
Lead-time cost per shipment = Period carrying cost ÷ Shipments in period

Where:

  • Average daily replenishment value = currency committed per day
  • Supplier lead time = replenishment days
  • Annual carrying cost rate = annual percentage as a decimal
  • Reporting period days = period matched to shipment volume
  • Shipments in period = outbound shipment count

Assumptions: The model uses a 365-day year and treats lead-time inventory value as steady over the reporting period. It does not add freight, duty, or supplier invoice charges.

What the result means

Use the primary result together with the supporting values to evaluate the specific supply-chain scenario represented by your inputs.

This calculator is a planning estimate. Operational definitions, data quality, and local business rules can change how the result should be applied.

Given:

  • Average daily replenishment value = $15,000/day
  • Supplier lead time = 16 days
  • Annual carrying cost rate = 18%
  • Reporting period = 30 days
  • Shipments = 1,000

Calculation:
Lead-time inventory value = $15,000 × 16 = $240,000
Annual carrying cost = $240,000 × 18% = $43,200
Period carrying cost = $43,200 × 30 ÷ 365 = $3,550.68
Cost per shipment = $3,550.68 ÷ 1,000 = $3.55

Result: Approximately $3.55 of supplier lead-time carrying cost per shipment.

Interpretation: Holding all other assumptions constant, reducing supplier lead time would lower the inventory value tied up and therefore lower this allocated per-shipment cost.

Is this amount the fee charged by the supplier?

No. It is an internal carrying-cost allocation associated with inventory tied up during lead time, not an invoice or freight charge.

Why use daily replenishment value instead of units?

Carrying cost is applied to inventory value. Daily value lets the calculator convert lead-time demand directly into the monetary amount exposed to carrying cost.

Can I compare domestic and overseas suppliers with this tool?

Yes, if you keep the valuation and carrying-cost methodology consistent. Add freight, duty, and risk costs separately when they differ materially.

Should safety stock be included in daily replenishment value?

Not automatically. This model isolates average lead-time inventory; separately held safety inventory can be evaluated with a safety-inventory cost estimator to avoid double counting.

How does shipment volume affect the result?

The total period carrying cost is spread across the entered shipments. Higher shipment volume lowers the allocated cost per shipment even though the lead-time inventory burden itself is unchanged.