XBKit·Amazon

Reorder Point Calculator

Know exactly when to place your next inventory order so you never run out of stock during supplier lead time.

Inventory Data

Total days from placing order to receiving at FBA or warehouse.

Use our Safety Stock Calculator to find this value, or enter 0 for no buffer.

Formula
Reorder Point=(Avg Daily Sales × Lead Time)+Safety Stock
  • When inventory = ROP → order now
  • Demand during lead time—
  • Days of total stock at ROP—

How to Use

  1. 1

    Enter your average daily sales

    Input how many units you sell per day on average. Use your last 30-day average for a stable figure.

  2. 2

    Enter supplier lead time

    Enter the number of days from when you place an order to when stock arrives at your warehouse. Include production, transit, customs clearance, and prep time.

  3. 3

    Add safety stock days

    Add extra buffer days for demand spikes or supplier delays. 7–14 days is common for FBA sellers. The tool factors this into the reorder point.

  4. 4

    See your reorder point

    The result tells you: when your inventory drops to this number of units, place your next order immediately.

Frequently Asked Questions

What is a reorder point?

The reorder point (ROP) is the inventory level that triggers a new purchase order. Formula: ROP = (Average Daily Sales × Lead Time in Days) + Safety Stock. When your stock reaches the ROP, you need to reorder immediately to avoid stockouts during lead time.

What should I use as my lead time for Amazon FBA?

For China-sourced products going to Amazon FBA via sea freight: total lead time is typically 45–75 days (production 15–30 days + sea transit 25–35 days + customs + prep + FBA receiving). Use 60 days as a conservative estimate if you don't have your own data.

How does safety stock affect the reorder point?

Safety stock is the buffer inventory you keep above your ROP to handle unexpected demand increases or supplier delays. More safety stock = higher ROP = you reorder earlier. Too much safety stock ties up capital; too little risks stockouts.

What happens if I miss my reorder point on Amazon?

Running out of stock on Amazon loses your sales history momentum, causes ranking drops (Amazon's algorithm rewards consistent sales velocity), and gives competitors time to capture your customers. Stockouts are expensive — chronic stockouts can cost 2–4x the lost revenue in recovered ranking costs.

Related Tools

Safety Stock CalculatorInventory Turnover CalculatorFBA Profit Calculator