Amazon FBA Restock Calculator

How do I calculate my Amazon reorder point? Reorder Point = (Lead Time + Safety Stock Days) × Daily Sales Velocity. For example, if you sell 5 units/day, your supplier takes 30 days, and you want 14 days of safety stock, your reorder point is (30 + 14) × 5 = 220 units. Place your order when FBA stock drops to 220 units.

Enter your current stock, sales velocity, and supplier lead time to find your exact reorder date, reorder point, and recommended order quantity — before you stock out.

Current Inventory
Total units sold in the last 30 days
Supplier Lead Time
days
Time from placing order to FBA check-in
days
Buffer days before stockout to trigger reorder
Order Planning (optional)
days
How many days of stock you want after arrival
Your supplier's MOQ (optional)
Days Until Stockout
—
Reorder In
—
Reorder Date
—
Inventory Breakdown
Daily Sales Velocity —
Current Stock —
Reorder Point —
Stock at Reorder Date —
Days of Cover (now) —
Already know your profit? Calculate your FBA margin before reordering → /profit-calculator.html

Restock alerts — automatically, for every SKU

SellerGuards connects once via Amazon SP-API. We track your FBA inventory levels in real time and alert you before you stock out — no spreadsheets, no manual checking.

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Frequently Asked Questions

How do I calculate my Amazon reorder point?

Reorder Point = (Lead Time + Safety Stock Days) × Daily Sales Velocity. For example, if you sell 5 units/day, your supplier takes 30 days, and you want 14 days of safety stock, your reorder point is (30 + 14) × 5 = 220 units. Place your order when FBA stock drops to 220 units.

What is safety stock and how many days should I use?

Safety stock is a buffer of inventory to protect against demand spikes and supplier delays. Most FBA sellers use 14–30 days. If your supplier is reliable and demand is stable, 14 days is fine. For seasonal products or international suppliers, use 30+ days.

How do I find my daily sales velocity?

In Seller Central, go to Reports → Business Reports → Detail Page Sales and Traffic. Look at your Units Ordered over the last 30 days and divide by 30. Alternatively, check your FBA inventory page which shows a “Days of Supply” estimate.

What should I include in supplier lead time?

Lead time is the full time from placing your purchase order to stock being available at Amazon FBA — including manufacturing time (if applicable), transit time to your location or 3PL, prep and labeling time, shipping to Amazon, and Amazon’s check-in processing time (typically 3–7 business days). Underestimating lead time is the most common cause of stockouts.

What is “days of cover” and what’s a good target?

Days of cover (or days of supply) is how many days your current stock will last at your current sales rate. A healthy FBA seller typically targets 45–90 days of cover: enough to never stock out, but not so much that you’re paying excess storage fees. For fast movers, 45–60 days. For slow movers, 60–90 days.