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Shipping, Ecommerce & WarehouseGenerated accuracy model review: 2026-05-06

Safety Stock Calculator accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

  • Safety stock = z-score * daily demand standard deviation * sqrt(lead time days).

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

  • Daily Demand Std Dev: 18 units/day
  • Lead Time: 14 days
  • Service Level: 95% service level

Expected outputs

  • Estimated Safety Stock: 112 units
  • Z-Score Used: 1.65
  • Lead-Time Demand Std Dev: 67.35 units

Known limitations

  • These calculators do not forecast demand automatically, fetch live provider rates, optimize warehouse layout, model taxes, or replace review of your contracts, carrier invoices, WMS data, accounting policies, or operations plan.

Assumptions

  • All demand, service, storage, labor, packaging, shipping, software, and handling values are user-entered assumptions.
  • No current carrier rates, 3PL fee cards, marketplace rules, or provider-specific costs are hardcoded.
  • Results are deterministic planning estimates and are not operations, accounting, tax, legal, or carrier-contract advice.
  • Calculations run locally in the browser without uploading private inventory, customer, order, or warehouse data.

Unit handling

  • Daily Demand Std Dev accepts values in units/day.
  • Lead Time accepts values in days.
  • Service Level accepts one of the configured options.
  • Estimated Safety Stock is displayed in units.
  • Lead-Time Demand Std Dev is displayed in units.

Rounding rules

  • Number displays use up to 2 decimal places in the calculator UI.
  • Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current safety-stock-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Safety Stock Calculator.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

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