Updated March 2026

Reorder Point Calculator for Shopify Stores

The reorder point tells you exactly when to place a new purchase order — the inventory level at which you need to order more before you run out. Get it right and you never stock out or overstock. Get it wrong and you lose sales or tie up cash.

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Average Daily Sales (units)

Lead Time (days)

Safety Stock (units)

Don't know this? Calculate safety stock first

The Formula

Reorder Point = (Avg Daily Sales × Lead Time) + Safety Stock

Average daily sales — How many units you sell per day on average over the past 30-90 days.

Lead time in days — Days between placing an order with your supplier and receiving it.

Safety stock — Buffer inventory to protect against demand spikes and delivery delays. Use the safety stock calculator to find this number.

Worked Example

You sell a moisturiser that averages 8 units/day. Your supplier delivers in 21 days. You've calculated safety stock at 25 units.

Reorder Point = (8 × 21) + 25 = 168 + 25 = 193 units. When this SKU drops to 193 units, place your next order.

Tips for Shopify Merchants

✓ Use at least 30 days of sales data for your daily average. Shorter windows are noisy, especially for seasonal products.
✓ Include the full lead time — from when you place the order to when it's on your shelves and scannable, not just shipping time.
✓ Review reorder points after any supplier change. A new supplier with different lead times changes your reorder point.
✓ For products with long lead times (45+ days), consider ordering more frequently in smaller batches to reduce the cash tied up in inventory.

Skip the Spreadsheet

Alertr calculates sell rates, days of stock, and reorder quantities automatically from your Shopify data. No formulas, no manual updates — just daily alerts when it's time to reorder.

Related Calculators

Safety Stock Calculator

Frequently Asked Questions

What is a reorder point?

The reorder point is the inventory level at which you should place a new purchase order. When stock for a SKU drops to this number, it's time to reorder so that new stock arrives before you run out.

How is reorder point different from safety stock?

Safety stock is the buffer you keep as insurance. Reorder point includes safety stock plus the inventory you'll sell during the lead time. Reorder point = demand during lead time + safety stock.

Should I set different reorder points for different products?

Yes. Every SKU has different daily sales velocity and potentially different lead times. A one-size-fits-all reorder point will leave you overstocked on slow movers and understocked on best sellers.

Can I automate reorder point alerts?

Yes. Alertr calculates sell rates and days of stock for every SKU automatically and sends alerts when products approach their reorder point — via email or Slack.

Automate Your Inventory Calculations

Alertr tracks sell rates and sends reorder alerts automatically. Inventory forecasting and reorder alerts. Free tier available, no credit card required.

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