Supply Chain Lead Time Calculator
Sum all components of your total supply chain lead time — from supplier confirmation through to customs clearance — and add a safety buffer.
Results
What is it?
Total lead time is the end-to-end time from placing a purchase order to receiving goods in your warehouse, ready for sale or use. It encompasses supplier processing, manufacturing, quality inspection, transit, and customs clearance. Accurately knowing your lead time is essential for setting reorder points, safety stock levels, and avoiding stockouts. The 20% buffer accounts for common delays such as port congestion, customs holds, and production overruns.
How to use
Enter the typical number of days for each stage of your supply chain. If a stage does not apply (e.g., no customs for domestic orders), enter 0. The calculator sums all stages and computes a safe planning lead time with a 20% buffer. Use the safe lead time when setting your reorder triggers.
Example scenario
A buyer imports electronics from China: 3 days supplier confirmation + 7 days production + 1 day QC + 14 days sea freight + 2 days customs = 27 days total. Safe lead time = 27 x 1.2 = 32.4, rounded to 33 days. The reorder point should be placed at least 33 days before projected stockout.
Pro tip
Track actual lead time for each supplier versus your estimate. Over 6-12 orders, you will identify which stage is most variable — that stage is where safety stock investment pays off most. Some buyers build a "worst-case" lead time using the 90th percentile of historical transit times rather than a flat percentage buffer.