How do you forecast demand for a Shopify store?

To forecast demand for a Shopify store, export 12 to 36 months of orders or the Total sales by product variant report, total units by SKU and month in Excel, and turn recent months into a daily demand rate. Multiply that rate by lead time plus safety stock for a minimum, and add a review period's demand for a maximum.

Does Shopify forecast demand?

Shopify's standard inventory reports describe the past: Inventory remaining per product, for example, divides current stock by the average daily sales of the last 28 days. That is a useful early warning, but it is not a forecast; it does not look at seasons or longer trends.

Shopify also points merchants to Sidekick, its AI assistant in Shopify admin, which it says can help you forecast demand, identify which products need replenishing and draft purchase orders. If you want to see and control the numbers yourself, a spreadsheet forecast is straightforward.

How do you get your sales history out of Shopify?

You have two exports to choose from. Either works.

1. Orders export: go to Orders, click Export, choose orders by date for the last 12 to 36 months, and pick CSV for Excel, Numbers, or other spreadsheet programs. Each sale line has its date, SKU and quantity. Large exports are emailed to you.
2. Report export: go to Analytics > Reports, open Total sales by product variant, set the date range, then use the horizontal menu and Export to save a CSV.
3. Also export current stock from Products > Inventory with Export, and note what is already on order from the Incoming column.

How do you calculate min and max in Excel?

Build one row per SKU with a demand rate, then apply four formulas. Keep everything in days.

1. Add a Month column to the sales export and build a pivot table with SKUs as rows, months as columns and quantity as values.
2. Daily demand = units sold in the last 12 months ÷ 365.
3. Min (reorder point) = daily demand × (supplier lead time days + safety stock days).
4. Max = min + daily demand × days between reviews.
5. Order quantity = max − available − incoming, rounded up to the supplier's pack size. Order only when available plus incoming is at or below min.

Example, using made-up data: Brightline Supply sold 1,095 units of a ceramic mug from Ironwell Goods in the last year, so daily demand is 3. Lead time is 14 days, safety stock 7 days, and the buyer reviews weekly. Min is 3 × 21 = 63, max is 63 + 21 = 84. With 40 available and none incoming, order 44, rounded to a case of 24 makes 48.

Shopify has no field to store the min, so use it as the threshold in a Shopify Flow low stock alert. Our Shopify reorder point guide shows how.

What are the common forecasting mistakes for online stores?

• Seasonality. A yearly average under-orders before a peak such as the holidays and over-orders after it. For seasonal SKUs, use the same months last year.
• Promotions and one-off spikes. A sale or a viral week inflates the average. Leave unusual weeks out or treat them separately.
• Stockouts. Days with nothing to sell record zero sales, which drags the average down. Leave sold-out periods out; the Month-end inventory snapshot report helps find them.
• Returns and canceled orders. Decide whether to subtract them, and do it consistently.
• Ignoring incoming stock. Always subtract what is already on a purchase order transfer.

How do you handle new and slow-selling products?

A new product has no history, so start from a similar product's sales and replace the estimate with real numbers after a few weeks. For a slow seller, count how many months had any sales. If it is only a few, plan to keep about one typical order in stock rather than trusting an average.

Where does ReorderOwl fit?

ReorderOwl replaces the spreadsheet. Export products, inventory and up to 36 months of orders from Shopify admin and attach them in ChatGPT; Claude setup is coming shortly. It is free to start.

It forecasts each product from your order history, compares that with stock at each location, and returns a workbook showing what to order, how much and from which vendor. When you ask, it builds the purchase order for you to send to your supplier. Nothing is installed in or written to Shopify. See ReorderOwl for Shopify.

Frequently asked questions

Can Shopify forecast inventory demand?

Its standard reports show history, such as days of inventory remaining from the last 28 days of sales. Shopify says its Sidekick assistant can help forecast demand.

How much Shopify history should I use?

Use 12 months for the demand rate and up to 36 months to check whether seasonal peaks repeat.

Which Shopify export is best for forecasting?

The orders export or the Total sales by product variant report. Both give sales by SKU that you can total by month.

What is the min max formula?

Min equals daily demand times lead time plus safety stock days. Max equals min plus daily demand times the days between reviews.

Where do I put the min in Shopify?

Shopify has no reorder point field, so use the min as the threshold in a Shopify Flow low stock alert or keep it in your spreadsheet.

Sources

1. Exporting orders, Shopify Help Center, accessed 2026-10-01
2. Sales reports, Shopify Help Center, accessed 2026-10-01
3. Inventory reports, Shopify Help Center, accessed 2026-10-01
4. Exporting reports, Shopify Help Center, accessed 2026-10-01
5. Transitioning from Stocky, Shopify Help Center, accessed 2026-10-01