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Lead Time Calculator

Calculate total lead time, reorder point, safety stock, and EOQ for supply chain and manufacturing operations. Supports simple, multi-stage, and demand-variability models.

Lead time · Reorder point · Safety stock · EOQ · Service level · Timeline visualization

Calculation Mode

Choose how to calculate your lead time

Simple

Single supplier lead time + reorder point

Multi-Stage

Sum of production, shipping, inspection stages

With Variability

Safety stock from demand & lead time variability

Lead Time & Demand

units/day
units
units
units
days

EOQ & Order Cost Inputs

units/yr
$
/order
$
/unit/yr
Quick Examples
Quick Summary
—
Reorder Point (units)
Lead Time—
Daily Demand—
Safety Stock—
Demand during LT—
Key Formulas
ROPD×LT + SS
Safety StockZ×σ_D×√LT
EOQ√(2DS/H)
Cycle StockEOQ / 2
Orders/yrD / EOQ
Service Level Z-Scores
90%Z = 1.282
95%Z = 1.645
97.5%Z = 1.960
99%Z = 2.326
99.9%Z = 3.090
Glossary
Lead Time — Time from order placement to receipt
ROP — Reorder Point: inventory level triggering a new order
Safety Stock — Buffer against demand/supply variability
EOQ — Economic Order Quantity: optimal order size
Cycle Stock — Average inventory between orders (EOQ/2)