Inventory Planner
Forecast your inventory needs, track stock levels across warehouses, set replenishment targets, and prevent stockouts, all from a single view.
Difficulty: 🟡 Intermediate · Reading time: ~15 min
Open this page in your dashboard: Go to Inventory Planner →
📋 Overview
The Inventory Planner page helps you stay ahead of stockouts and overstocking. It combines real-time stock levels, sales velocity calculations, and demand forecasting to tell you exactly how much inventory to send, and when. Whether you sell via FBA or FBM, across one marketplace or ten, this tool keeps your supply chain healthy.
Why this matters: Stockouts cost more than just lost sales. Amazon penalizes your organic ranking, your PPC spend is wasted, and competitors capture your Buy Box. A single week out of stock on a top seller can take 2-4 weeks of recovery to regain your previous ranking position.
📊 Key Performance Indicators
Six KPI cards sit above the table. Each reflects the products in your current view (the active filters), and each is clickable to filter the table, see Interactive KPI cards below.
Total Products
All active products in the current view
Need Restock
Products where Units to Send is greater than 0 (critical + low + stranded out-of-stock)
Out of Stock
Strict: 0 current stock and 0 inbound (items with inbound en route show in the sub-line and under Critical status)
Healthy Stock
Healthy + overstocked products; the sub-line shows the split and surfaces no-sales (dead-inventory) count
Fully Stocked
Slow movers, dead stock, new listings, and other low-velocity rows not in the restock or OOS buckets
Units to Send
Sum of recommended replenishment units across all products in the view
Quick win: If your "Need Restock" number is greater than zero, address those products first. Click the Need Restock card to filter the table to exactly those rows, then sort by "Days Left" ascending to prioritize the most urgent items.
Interactive KPI cards
The KPI cards are not just headline numbers, click a card to filter the table to those products:
Click Need Restock, Out of Stock, Healthy Stock, Fully Stocked, or Units to Send to instantly filter the table to that group. The clicked card is highlighted as active and the table jumps back to page 1.
Click the same card again (or click Total Products) to clear the filter and show everything.
Only one KPI filter is active at a time; it stacks on top of the regular filters (Marketplace, Fulfillment, etc.).
Why this matters: This turns every KPI into a one-click triage shortcut. See "12 need restock"? Click it and you're looking at precisely those 12 SKUs, no manual sorting or searching required.
Inventory Table
For your first week: Focus on just 4 columns : Current Stock, Daily Sales Avg, Days Left, and Status. These tell you what needs restocking now. The remaining columns become useful as you scale.
A complete, 14-column interactive table with full sorting, search, and pagination:
Product
Product name, image, SKU (Stock Keeping Unit), ASIN (Amazon Standard Identification Number), FNSKU
Current Stock
Units currently available in Amazon warehouses
Inbound
Units in transit to Amazon (shipped but not yet received)
Reserved
Units reserved for pending orders or processing
Pending Transfers
Units being transferred between fulfillment centers
Daily Sales Avg
Average units sold per day (based on lookback period)
Expected Sales
Projected units to sell during target replenishment period
Days Left
Estimated days until current stock runs out
Units to Send
Recommended replenishment quantity
Status
Color-coded badge (see below)
Stock Bar
Segmented visual bar showing inventory composition
Expected OOS (Out of Stock) Date
Projected out-of-stock date
"Days Left" and "Expected OOS Date" count stock differently. Days Left divides your available stock - current stock plus inbound and pending transfers - by daily velocity, so it reflects everything already in the pipeline. Expected OOS Date is deliberately stricter: it projects from your current on-hand stock only and ignores inbound, answering "when do I run dry if nothing new arrives?" That is why the OOS date can fall sooner than Days Left implies.
Status Badges
Critical
Red
Stock will run out within days
Low
Orange
Stock below target, reorder soon
Healthy
Green
Stock within target range
Overstocked
Blue
More stock than needed for the target period
No Sales
Gray
Product has no recent sales data
Out of Stock
Dark Red
Zero units available
Stock Bar Visualization
Each product row includes a segmented bar showing:
Green: Current available stock
Blue: Inbound units
Purple: Reserved units
Orange: Units to send (replenishment needed)
👣 Step-by-Step Example: Calculating a Reorder
Here is a realistic scenario showing how SellerMagnet calculates reorder recommendations:
Scenario: You sell a garlic press (ASIN: B09EXAMPLE1) on Amazon.de. Your supplier is based in Shenzhen, China.
SellerMagnet's calculation:
Expected Sales during target period: 8 units/day x 42 days = 336 units
Current Stock + Inbound: 120 + 0 = 120 units
Units to Send: 336 - 120 = 216 units
Days Left at current rate: 120 / 8 = 15 days (Status: Critical)
Expected OOS Date: 15 days from today
Current Stock
120 units
Inbound
0 units
Daily Sales Avg (30-day lookback)
8 units/day
Supplier Lead Time
21 days (production)
Shipping to Amazon FBA
14 days (sea freight + customs)
Safety Buffer
7 days
Total Target Days
42 days
Action required: In this example, you have only 15 days of stock but your total replenishment cycle is 42 days. You need to place an emergency order immediately, or consider air freight to bridge the gap.
Reorder Calculation Template
Use this template to configure your Target Days slider for each product category:
Supplier Production Time
___ days
Time from PO to goods ready
Shipping to Amazon
___ days
Transit + customs + FBA check-in
Safety Buffer
___ days
Extra cushion (7-14 days recommended)
Total Target Days
___ days
Set your slider to this value
Best practice: Create a spreadsheet with these values for each supplier. Your Target Days should reflect your slowest supplier if you cannot filter by product group.
🔍 Filters
Marketplace
All Marketplaces, EFN (Pan-EU), or a specific marketplace
All
Lookback Days
7, 14, 30, 60, 90, 180, 365 days (for velocity calculation)
30 days
Fulfillment Type
FBA, FBM
All
Condition
New, Used - Like New, Used - Very Good, Used - Good, Refurbished
All
Listing status
All, or Active only (see below)
All
View
All, Need attention, Fully stocked, Slow movers (see below)
All
Target Days (chips)
14, 30, 60, 90 days, or Custom (1-365)
30 days
Hide 0 to send
Toggle chip - hides rows where Units to Send is 0
Off
Listing-status filter (All vs Active only)
A listing that has gone Inactive, Incomplete, or Expired on Amazon can still hold stock, so by default the tool shows All listings, that way suppressed listings sitting on inventory stay visible (they carry a yellow/red badge in the product cell).
All - show every listing, including Inactive / Incomplete / Expired ones.
Active only - hide suppressed / incomplete / expired listings and show just the ones currently live on Amazon.
Why this matters: Stock trapped on a suppressed listing is easy to forget. Leave the filter on All when you audit for stranded inventory; switch to Active only when you just want a clean picture of your sellable catalog.
View quick-filter chips
A row of View chips slices the table by replenishment urgency in one click:
All
Every product in the current view
Need attention
Rows that need action - Units to Send greater than 0, or stranded out of stock
Fully stocked
Healthy and overstocked rows
Slow movers
Has stock but 0 sales in the lookback window - dead inventory
Quick win: Click Slow movers every few weeks to surface dead stock, units sitting in the warehouse with no recent sales, before they rack up long-term storage fees.
Pro tip: Use a 7-day lookback during fast-moving periods (Prime Day, Black Friday) to capture spikes. Switch back to 30 days during normal periods for a more stable average.
Choosing the Right Lookback Period
7 days
Capturing recent trends, during promotions
Overreaction to one-off spikes
14 days
Balanced short-term view
May still reflect temporary promotions
30 days
Stable average, most sellers' default
May lag behind seasonal shifts
60 days
Smoothing out mid-term seasonality
Slower to react to a genuine trend change
90 days
Long-term trending, slow-moving inventory
Ignores recent sales velocity changes
180 / 365 days
Very slow movers and yearly seasonal SKUs
Heavily dampens any recent change in demand
EFN (Pan-European) Mode
If you use Amazon's European Fulfillment Network (EFN), the tool automatically aggregates inventory for the same ASIN across EU marketplaces (DE, FR, IT, ES, NL, SE, PL, BE). Stock levels use the maximum values (shared pool), while sales velocity is summed across all participating marketplaces.
EFN (European Fulfillment Network) mode ensures your forecasting accounts for the shared inventory pool, preventing duplicate reorder recommendations.
Pan-European sellers: If you recently switched from EFN to Pan-EU (where Amazon distributes stock across multiple country warehouses), your inventory data will shift. Allow 2-3 days for SellerMagnet to recalibrate stock positions after a fulfillment network change.
"Group by" control (SKU / Listing / Marketplace)
When you sell on more than one marketplace, a Group by control appears in the toolbar. It decides how the same product spread across countries is rolled up into table rows:
SKU
One row per origin SKU (aggregated across marketplaces)
Pan-EU / EFN sellers who manage a shared pool
Listing
One row per (SKU, marketplace) listing
Reviewing each country's listing individually
Marketplace
Raw rows, one per marketplace, no grouping
Seeing untouched per-marketplace stock and sales
Multi-marketplace columns. With more than one marketplace connected, the table also gains explicit Condition and Fulfillment columns so you can tell an FBA row from an FBM row, and a New listing from a Used one, at a glance.
Per-Product Forecast Chart
Click the chart icon on any product row to view a detailed stock forecast for that individual product:
Historical stock levels
Projected depletion timeline
Recommended reorder point
Expected out-of-stock date
Forecast KPI cards
Four KPI cards sit at the top of the forecast modal and summarise the reorder decision for that single SKU:
Recommended Order Qty
Suggested reorder quantity, sized from velocity, current stock, and your Lead time / Safety inputs
Recommended Order Date
The date to place the order so it lands before you run dry
Cost of next batch
The recommended order quantity multiplied by your unit COGS (Cost of Goods Sold), i.e. what that batch will cost from your supplier
Lost revenue at OOS
Projected revenue you would lose if the SKU goes out of stock, the demand during the stock-out gap multiplied by the unit price
These two cards need your cost and price data. Cost of next batch only shows a figure once a supplier COGS is on file for the product (otherwise it reads "Needs supplier cost"), and Lost revenue at OOS needs a selling price and measurable sales velocity. If current stock already covers the lead time, Lost revenue at OOS correctly shows zero, nothing is at risk.
Why it matters: Together these turn the forecast into a money decision, not just a units one. You see the cash the next purchase order ties up and the revenue you stand to lose by not placing it, side by side.
"What-if" reorder simulator
Below the forecast chart is a what-if slider that lets you preview the impact of a reorder before you place it. Drag the slider to a quantity (it starts anchored at the recommended order quantity) and the chart draws a separate "Simulated (your order)" series on top of the existing forecast line.
The simulated order is assumed to arrive after your configured lead time - so the bump in the line appears on the day the shipment would land, not today.
From its arrival day, the simulated stock depletes at the product's daily sales velocity, just like real inventory.
This lets you see at a glance how a given order size pushes out your projected stock line and your out-of-stock date.
It builds on the real forecast. The simulated line starts from the same baseline as the orange forecast line (which already accounts for inbound shipments and reservations) and adds your hypothetical order on top - so the two lines stay aligned and you only see the difference your order makes. Adjust the Lead time and Safety days inputs first; they feed both the recommendation and where the simulated order lands.
Why it matters: Before committing to a purchase order, slide the quantity up or down to find the smallest order that still clears your out-of-stock gap. Order too little and the line still dips to zero; order too much and you can see the overstock building on the tail of the curve.
Exporting the forecast series
The per-product forecast modal has its own Export menu so you can pull that single SKU's projected curve out as a spreadsheet. Choose CSV or Excel (.xlsx), the file is named after the product's SKU and contains the day-by-day series:
date
Each day in the forecast horizon
projected_stock
Projected units remaining on that date
recommended_order_date
Your recommended reorder date (on the first row)
projected_oos_date
The expected out-of-stock date (on the first row)
Why it matters: Export a specific SKU's depletion curve to drop straight into a supplier PO discussion or a reorder spreadsheet, without exporting the whole catalog.
Actions
Search
Filter by product name, SKU, ASIN, or FNSKU
Column Toggle
Show/hide columns to customize your view, remembered as your default (see below)
Export
Download the table as CSV or Excel; the per-product chart exports its forecast series
Print-optimized view (UI elements removed)
Refresh
Manual data reload
Saved Default View
The Columns menu lets you tailor which columns appear, and SellerMagnet remembers your choice as your default view so you don't have to reconfigure it on every visit.
Open the Columns menu and tick or untick columns, or use a Quick view preset: Default (the standard column set) or Print-friendly (just Product, Units to Send, and Days Left for a clean warehouse pick-list).
A footer in the menu confirms the contract: "Saved as your default view."
Your column choice persists across sessions and across devices, it is saved to your account (per user), not just to one browser, so signing in on another machine inherits the same layout. The Print layout honours the same visible columns.
To return to the standard layout, pick the Default quick view, which also clears the saved preference.
Columns are remembered; filters are not. Your column layout is a saved display preference. The data filters (Marketplace, Lookback, Target Days, etc.) deliberately reset each visit so you always start from a clean, current view.
Why it matters: Set a lean column view once, e.g. Product, Units to Send, Days Left for warehouse pick-lists, and every visit and printout uses it automatically.
🔄 Before & After: Impact of Using Inventory Management
Stockout frequency
3-5 products/month
0-1 products/month
Overstock (excess units)
40% of catalog
Under 10% of catalog
Manual spreadsheet time
4-6 hours/week
0 hours (automated)
Revenue lost to stockouts
~8-12% monthly
Under 2% monthly
Storage fee waste
High (overstocked SKUs)
Minimal
ROI example: A seller doing EUR 50,000/month who reduces stockout-related revenue loss from 10% to 2% recovers EUR 4,000/month, that is EUR 48,000/year in revenue that would have otherwise been lost.
Seasonal & Timing Advice
Q4 preparation (September-October): Increase your Target Days slider by 50-100% starting in September. Supplier lead times stretch during peak season, and Amazon's FBA receiving windows become slower. If your normal target is 45 days, consider setting it to 70-90 days for Q4 SKUs.
Post-holiday (January-February): After the holiday rush, switch your lookback to 90 days temporarily. A 7- or 14-day lookback in early January will show artificially low sales velocity and cause you to under-order for February/March recovery.
Prime Day (typically July): Two weeks before Prime Day, switch to a 7-day lookback for any products included in Lightning Deals or promotions. Revert to 30 days one week after the event.
⚠️ Common Mistakes to Avoid
Mistake 1: Using a lookback period that is too short during product launches. New products with only 7 days of sales history will have unreliable velocity calculations. Wait until you have at least 14-30 days of data before relying on automated reorder recommendations.
Mistake 2: Ignoring inbound shipments in your calculations. If you have 200 units inbound and the tool shows 200 "Units to Send," you do not need to send 200 more. The inbound column already factors into the recommendation, but double-check that your inbound shipment is actually moving (not stuck at "Checked In" for weeks).
Mistake 3: Setting the same Target Days for all products. A product sourced from a local warehouse (3-day lead time) and a product from overseas (45-day lead time) should not share the same Target Days. Use the slider as a global default, but review individual SKUs that deviate from your typical supply chain.
Mistake 4: Not accounting for Amazon's receiving delays. During Q4 or after major sale events, Amazon warehouses can take 1-3 weeks to check in your inventory. Factor this into your Target Days. Your goods are not sellable until they appear as "Available."
Mistake 5: Overstocking slow-moving SKUs. Just because a product is "Low" does not mean you should send 6 months of stock. For slow sellers (under 1 unit/day), overstocking triggers long-term storage fees. Keep target days conservative for these items.
## 🔧 Troubleshooting
Why is my inventory not syncing?
Check your Amazon SP-API (Selling Partner API) connection. Navigate to Settings > Connections and verify your Amazon marketplace shows a green "Connected" status.
Verify the correct marketplace is selected. If you are filtering by Amazon.de but your inventory is on Amazon.com, you will see no data.
Allow time after initial setup. First-time syncs can take 15-60 minutes depending on catalog size. Look for the "Last Synced" timestamp at the bottom of the page.
Check Amazon Seller Central. If Seller Central itself is showing delayed data (common during peak periods), SellerMagnet will reflect the same delays.
Why does "Units to Send" show zero for a product I know needs restocking?
Your inbound shipments may already cover the expected demand. Check the "Inbound" column.
The "Hide Zero Units to Send" filter may be off but the lookback period might show low sales. Try switching from 30 to 14 days.
The product might have zero sales in the lookback period, resulting in a "No Sales" status.
Why is my Daily Sales Avg different from what I see in Seller Central?
SellerMagnet calculates the average using the lookback period you selected. Seller Central may use a different time window. Additionally, SellerMagnet excludes days when you were completely out of stock from the velocity calculation (to avoid deflating the average).
My forecast chart shows a sudden drop: what happened?
A sudden drop usually indicates either: (a) a bulk order or promotion that spiked sales, (b) a shipment that was received and then quickly sold, or (c) an inventory adjustment by Amazon (removed or transferred units). Check your Reimbursements page for any lost/damaged inventory events around that date.
❓ FAQ
Does SellerMagnet account for out-of-stock days when calculating sales velocity?
Yes. Days when your product had zero available stock are excluded from the Daily Sales Avg calculation. This prevents the average from being artificially deflated by stockout periods and gives you a more accurate reorder quantity.
Can I set different Target Days for different products?
The Target Days slider applies globally to all products in the current view. For product-level customization, use the per-product forecast chart to manually assess individual SKUs with different lead times.
How often does inventory data refresh?
Inventory data syncs automatically every 2-4 hours via the Amazon SP-API. You can trigger a manual refresh at any time using the Refresh button.
Does this work for FBM (Merchant Fulfilled) products?
Yes. Switch the Fulfillment Type filter to FBM. For FBM products, "Current Stock" reflects the inventory count you have reported to Amazon. Sales velocity and forecasting work the same way.
What happens if I sell on multiple EU marketplaces with EFN?
SellerMagnet automatically detects EFN enrollment and aggregates your inventory. You will see one consolidated row per ASIN instead of separate rows per marketplace, with combined sales velocity across all EU marketplaces.
Can I export the data to share with my supplier?
Yes. Click Export and choose CSV or Excel. The export includes all visible columns, so use the Column Toggle to include or exclude fields before exporting. Many sellers send the file directly to their supplier with the "Units to Send" column highlighted. (For a printout, the Export menu also has a Print option that uses the same visible columns.)
Why does the Expected OOS Date keep changing?
The Expected OOS Date is recalculated on every data sync based on your current stock level and the most recent sales velocity. If your sales speed up (e.g., a competitor goes out of stock), the OOS date moves closer. If sales slow down, it moves further out.
💡 Tips
Pro tip: Set your Target Days slider to match your supplier lead time + shipping time. For example, if your supplier needs 15 days to produce and 10 days to ship to Amazon, set the target to 30-40 days (with buffer).
Filters are saved between sessions via local storage, so your preferred view persists when you return.
Pro tip: Export your inventory report every Monday morning and compare it to the previous week. Look for any product that shifted from "Healthy" to "Low", those are your priority reorders for the week.
Pro tip: If you run Lightning Deals or Coupons, temporarily reduce your lookback to 7 days for the week after the promotion ends. This helps you see whether the elevated sales velocity is sustainable or a one-time spike.
➡️ What's Next?
Fee AuditReimbursements (Lost & Found)Last updated