Shopify Inventory Forecasting for High-SKU Stores

Forecast Demand for Every Shopify SKU - Not Just the Top Sellers

Every day you are out of stock, you are losing money. Shopify does not tell you when to reorder. It tells you when you are already low, which is the wrong moment to learn it.

ReplenishRadar connects to your Shopify store and:

• Predicts demand for each SKU based on its own sales history
• Alerts you when it is time to order, not when it is already too late
• Generates PO drafts so reorders take seconds, not afternoons

Built for Shopify Stores with 1,000 to 50,000 SKUs

Most Shopify forecasting tools are designed for stores with a few hundred listings. They work fine until your catalog crosses about 1,000 active SKUs, at which point a category-level forecast starts hiding more than it reveals. We built ReplenishRadar specifically for the high-SKU end of Shopify: operators running 1,000 to 50,000 active products, often across Shopify Plus, sometimes layered on top of Amazon FBA, and almost always with mixed demand patterns inside a single collection.

If your catalog is small, this is overkill. If you are on Shopify Plus with a long tail of SKUs that the spreadsheet keeps mis-forecasting, this is exactly where ReplenishRadar earns its keep. Still weighing the options? Our guide to the best Shopify inventory management software scores the main tools side by side so you can see where each one fits.

How It Works

1. Connect Your Store

One-click Shopify OAuth. We read your products, inventory, orders, and refund data. Historical orders are backfilled in yearly chunks, up to 10 years of history via the read_all_orders scope.

2. Pull Shopify Order Data at the SKU Level

We sync your order line items from the Shopify Orders API, not just aggregated daily totals. That means every variant, every quantity, every refund maps back to the SKU it was sold on. Bundles get expanded into their component SKUs so a kit sale draws down each part correctly. Refunds are subtracted automatically, so the forecast you see is net demand, not gross.

If you sell the same SKU across multiple Shopify locations, demand is aggregated up to the SKU level for forecasting and then split back down for replenishment per location. The system never asks you to manage that mapping by hand.

3. See Per-SKU Forecasts

Within 24 hours of the first sync, you will see demand predictions for every product. We forecast at the SKU level, so each product gets the model that fits its actual sales pattern. Steady sellers get exponential smoothing. Seasonal items get time-series decomposition once you have 24+ months of history. Intermittent SKUs get methods built for sparse, lumpy demand.

Each forecast extends 12 weeks out, with confidence indicators per SKU so you can see which numbers are reliable and which are best guesses on thin data.

4. Handle Lead Times Per Supplier - Not Per Product

Every supplier in your account has its own stated lead time and its own ordering cadence. Weekly, monthly, or specific days of the month: you set it once when you onboard the vendor and the math respects it from then on. If your overseas factory wants POs on the 1st and 15th and your domestic packaging supplier accepts orders any day, both rules get baked into the reorder suggestions automatically.

We also track actual delivery performance against the stated lead time across every PO you have placed. If a supplier consistently runs 4 days late, the reorder math expands the buffer for that vendor without you having to inflate the lead time everywhere. That is captured in the supplier scorecard and feeds back into every forecast that depends on that vendor.

5. Get Reorder Alerts at the Right Moment

When it is time to order, you will know. Alerts factor in the per-SKU demand forecast, the per-supplier lead time, the safety stock target you set, and the next available ordering window for that vendor. The output is a list of SKUs that need POs this week, grouped by supplier, with suggested quantities you can edit before sending.

6. Draft POs and Get Real Supplier Replies

Convert forecasts into purchase order drafts instantly. Download a PDF or Excel (XLSX) packet for your supplier or ERP, or send the supplier a secure response link so they confirm quantities, share ship dates, upload invoices, and update receipt milestones in the same PO record your team is looking at.

7. Let Shopify Flow Route the Alerts

ReplenishRadar shows up natively in Shopify Flow with five triggers (stockout risk, forecasted stockout, days-of-cover too low, drafted PO, FBA discrepancy) and two actions (approve PO, send to alerts). Five ready-to-import recipes live in the recipe library. Inventory triggers are included on Standard and up; PO approval and FBA discrepancy are on Growth and up.

Designed for Shopify Operators Who:

• Run 1,000 to 50,000 active SKUs on Shopify or Shopify Plus
• Order from multiple suppliers with different lead times and ordering cadences
• Carry a mix of steady, seasonal, and slow-moving products in the same catalog
• Have outgrown spreadsheets but do not want an ERP
• Sell through Shopify alone, or alongside Amazon FBA

Pricing

Standard: $99/mo

• 2 connected stores
• Up to 2,000 active SKUs
• 1,000 sales line items/month
• Demand forecasting
• Purchase order generation
• Real-time updates plus 24-hour accuracy checks
• Free inventory report

Growth: $199/mo

• 5 connected stores
• Up to 20,000 active SKUs
• 5,000 sales line items/month
• Real-time updates plus 6-hour accuracy checks
• Triage Mode for catalog cleanup
• Vendor workflows

Scale: $499/mo

• 10 connected stores
• Up to 50,000 active SKUs
• Real-time updates plus hourly accuracy checks
• Forecast accuracy dashboards
• MCP package (AI agent access)

Start your free trial and scale as you grow. Want to see the numbers against your own catalog first? Get a free Shopify inventory report. Emailed the moment your first sync finishes.

ReplenishRadar is a Shopify Partner. Install in two clicks from the Shopify App Store:

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Learn More:

• Built into Shopify Flow - Five triggers and two actions, native inside Shopify Flow
• Supplier Portal - A secure response link on every PO
• SKU-Level Demand Forecasting - Per-SKU models and accuracy tiers
• Inventory Forecasting 101 - Understand the basics
• Reorder Point Calculator - How to set reorder points
• Shopify Inventory Sync Best Practices - Keep data accurate
• Best Multi-Channel Inventory Software - Compare the top multi-channel inventory tools
• Compare ReplenishRadar to alternatives - See how we stack up