Free Lead Time Calculator
Total supplier lead time formula
Add your order processing, supplier, shipping, and inspection times to calculate total lead time. Optionally enter daily demand to get your reorder point.
Lead Time Components (days)
Reorder Point (optional)
Enter daily demand to also calculate the reorder point
Formula: Total Lead Time = Processing + Supplier Lead Time + Shipping + Inspection
Reorder Point = Total Lead Time × Daily Demand
What Is a Lead Time Calculator?
A lead time calculator adds up each stage of your supply chain — from placing an order to receiving goods ready for sale. Knowing your total lead time lets you set accurate reorder points, avoid costly stockouts, and plan purchase orders with confidence. The standard formula is: Total Lead Time = Order Processing Time + Supplier Lead Time + Shipping Time + Inspection Time.
How to Calculate Lead Time in 3 Steps
Step 1 — Enter Each Time Component
Break down your total lead time into its four components: order processing time (admin + approval), supplier lead time (manufacturing/picking), shipping/transit time, and inspection or QC time on receipt.
Step 2 — Get Total Lead Time
The calculator instantly sums all components to give your total lead time in days. Use this to plan purchase orders and avoid stockouts.
Step 3 — Calculate Reorder Point (optional)
Enter your daily demand and the calculator will also show your reorder point — the stock level at which you should place a new order to arrive just in time.
Who Uses This Lead Time Calculator?
Procurement Managers
Calculate accurate lead times across multiple suppliers to plan purchase orders and avoid stockouts during peak periods.
Inventory Planners
Use total lead time to set precise reorder points and safety stock levels for each SKU.
E-commerce Businesses
Understand how long it takes from placing an order to having goods available, so you can promise accurate delivery dates to customers.
Supply Chain Analysts
Identify which component of lead time is the biggest bottleneck and focus reduction efforts for maximum impact.
Frequently Asked Questions
What is lead time in inventory management?
Lead time is the total number of days between placing a purchase order and receiving the goods in your warehouse ready for sale. It includes order processing, supplier production/picking, shipping, and any inspection on receipt.
What are the components of lead time?
Order processing time (admin, approvals), supplier lead time (manufacturing or picking), shipping/transit time, and inspection or QC time. Some businesses also include internal putaway time.
How does lead time affect my reorder point?
Reorder Point = Total Lead Time × Average Daily Demand. A longer lead time means you need to trigger reorders earlier (at a higher stock level) to avoid running out before the new shipment arrives.
What is a good lead time for inventory?
It depends on your supply chain. Local suppliers may have 1–3 day lead times; overseas suppliers can be 30–90 days. Shorter lead times allow you to hold less safety stock and respond faster to demand changes.
How can I reduce lead time?
Work with suppliers closer to your location, use automated purchase orders to cut processing time, negotiate faster shipping options, pre-approve common items to skip QC delay, and maintain backup suppliers for critical SKUs.
Is this lead time calculator free?
Yes, completely free with no account or login required.