Free Tool

Reorder Point Calculator

Enter average daily demand, supplier lead time and a safety-stock buffer. The calculator adds demand during lead time to the buffer you enter. Use the result as a point to review an order, then check the sales period and lead time behind your inputs.

How to Calculate Your Reorder Point

Enter your average daily demand, supplier lead time, and safety stock buffer. The calculator returns your reorder point in units — the on-hand quantity at which you should trigger a new purchase order.

Avg Daily Demand (units/day)

Supplier Lead Time (days)

Safety Stock (units) — unknown? calculate it here

Review reorders with Forthcast.

Forthcast uses Shopify sales and inventory data to help plan reorders for products in its forecast workflow. Check which products appear in Reports, then review supplier settings and draft purchase orders before sending them.

See Forthcast features

Reorder Point Formula

The reorder point formula is:

            Reorder Point = (Average Daily Demand × Lead Time) + Safety Stock
        

Input	What it means	Example
Avg Daily Demand	Units sold per day, averaged over 30–90 days	15 units/day
Lead Time	Days from order to delivery (include transit + processing)	14 days
Safety Stock	Buffer units for demand spikes or late deliveries	30 units
Reorder Point	(15 × 14) + 30	240 units

Why Reorder Point Matters for Shopify Merchants

Setting the wrong reorder point is one of the most common causes of stockouts and overstock. Too low, and you run out before new stock arrives. Too high, and you tie up cash in inventory you don't need yet.

Lead time is the single biggest variable. A 7-day error in your estimated lead time shifts the reorder point by 7 × your daily demand — which could be hundreds of units on a fast-moving SKU.

How Forthcast Automates Reorder Points

This calculator uses the numbers you enter. Forthcast uses Shopify sales and inventory data with supplier settings to suggest reorders. Its main forecast set depends on sales history and active inventory. New products use separate seed forecasts. Demand forecasts and reorder points are store-wide, even when stock is shown by location. Review the proposed quantity, supplier and destination before sending a purchase order.

Frequently Asked Questions

What is a reorder point?

The reorder point (ROP) is the on-hand stock level at which you should place a new purchase order, so that new stock arrives just as you're running low. It equals demand during lead time plus your safety stock buffer.

How do I find my average daily demand?

Divide total units sold in a period by the number of days. For example, 450 units sold in 30 days = 15 units/day. Use a longer window (60–90 days) to smooth out outliers, and recalculate after significant demand shifts like promotions.

What should my safety stock be?

Set a buffer for the demand and delivery uncertainty you can see. Uneven sales or variable supplier lead times may call for a different buffer from a steady product. This calculator asks you to enter safety stock; it does not calculate that input. The separate safety-stock calculator gives you another estimate to review against your service target and inventory budget.

Is this reorder point calculator free?

Yes. The reorder point calculator on Forthcast is completely free — no signup required, no data stored.