How to Calculate Your Reorder Point (With Shopify Examples)

The reorder point formula is simple:

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

That's it. When your inventory hits that number, place your order. You'll get new stock right as you're about to run out, without overstocking.

But the formula is the easy part. The hard part? Getting accurate numbers for your store. Generic advice tells you to "calculate your average daily sales" without explaining where to find that in Shopify, or how to handle products that don't sell consistently.

This guide fixes that. I'll walk you through calculating reorder points for your actual Shopify products, with real numbers and practical examples. By the end, you'll have a system that tells you exactly when to reorder. No more gut feelings or spreadsheet guesswork.

What Is a Reorder Point (And Why It Matters)

Your reorder point is the inventory level that triggers a new purchase order. It's the "yellow warning light" for each product.

Think of it this way: if your supplier takes 14 days to deliver, you need to order before you run out. The reorder point tells you exactly when "before" is.

Get it right, and you:

• Never stockout on your bestsellers
• Stop tying up cash in excess inventory
• Spend less time manually checking stock levels

Get it wrong, and you either run out (losing sales and frustrating customers) or over-order (killing your cash flow).

Most Shopify merchants handle this by feel. They check inventory when they remember, order when something looks low, and cross their fingers. It works until it doesn't (usually during your busiest sales period).

A proper reorder point removes the guesswork. It's a number you can track, automate, and trust.

The Reorder Point Formula Explained

Let's break down each part of the formula:

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

Average Daily Sales

How many units of this product you sell per day, on average.

This isn't your best day or your worst day. It's the typical daily demand. You want enough historical data to smooth out fluctuations (usually 30-90 days, depending on how consistently the product sells).

Lead Time

The number of days between placing an order and receiving it in your warehouse, ready to ship.

This includes:

• Supplier processing time
• Manufacturing time (if made to order)
• Shipping/transit time
• Your receiving and quality check time

Lead time is often longer than merchants expect. If your supplier ships in 5 days but it takes 3 days to clear customs and another 2 days before you've checked it in and photographed it, that's 10 days, not 5.

Safety Stock

Your buffer for the unexpected. Supplier delays. Demand spikes. That influencer who suddenly features your product.

Safety stock is insurance. You're trading a bit of extra inventory cost for protection against stockouts. How much safety stock you need depends on how variable your demand and supply are (more on that shortly).

How to Calculate Your Reorder Point in Shopify (Step by Step)

Let's work through this with a real example. Say you sell a popular candle called "Autumn Woods" and you want to calculate its reorder point.

Step 1: Find Your Average Daily Sales

In Shopify:

1. Go to Analytics → Reports → Sales by product
2. Set the date range to the last 90 days (or 30 if it's a newer product)
3. Find "Autumn Woods" and note the total units sold

Let's say you sold 270 units over 90 days.

Average Daily Sales = 270 ÷ 90 = 3 units/day

If your product has strong seasonality (like, say, autumn-scented candles), you might want to calculate this for comparable periods. Your average daily sales in September will be higher than in March.

Step 2: Determine Your Lead Time

Contact your supplier or check your records. You need to know:

• How long from order to shipment?
• How long in transit?
• Any customs or inspection delays?
• How long before it's ready to sell?

Let's say your candle supplier ships within 3 days, transit takes 7 days, and you need 2 days to receive and shelve. Lead time = 12 days.

Be realistic here. Suppliers often quote best-case scenarios. If they sometimes take 5 days to ship, use 5 days. Or track your actual lead times over several orders to get a reliable average.

Step 3: Calculate Your Safety Stock

The standard safety stock formula is:

Safety Stock = (Maximum Daily Sales - Average Daily Sales) × (Maximum Lead Time - Average Lead Time)

This accounts for variability on both sides: demand spikes and supply delays.

For "Autumn Woods":

• Your average daily sales: 3 units
• Your busiest day in the last 90 days: 8 units (maybe a Saturday during a sale)
• Your average lead time: 12 days
• Your longest lead time: 16 days (that one order that got stuck in transit)

Safety Stock = (8 - 3) × (16 - 12) = 5 × 4 = 20 units

If you don't have data on maximum values yet (new product, new supplier), start with a simpler approach: 1-2 weeks of average sales as safety stock. For our candle: 3 units × 7 days = 21 units. Close enough.

Step 4: Calculate the Reorder Point

Now put it together:

Reorder Point = (Average Daily Sales × Lead Time) + Safety Stock Reorder Point = (3 × 12) + 20 = 36 + 20 = 56 units

When your "Autumn Woods" inventory hits 56 units, it's time to order more.

Want to plug in your own numbers without doing the math? Try the free reorder point calculator — enter units sold, lead time, and safety stock days, and the answer updates as you type.

A Complete Example: Three Products with Different Profiles

Theory is nice, but let's see how this works across different product types.

Product A: Steady Seller (Basics T-Shirt)

• Sells 10 units/day consistently
• Lead time: 21 days (overseas manufacturer)
• Demand is predictable (low variance)
• Safety stock: 7 days of average sales = 70 units

Reorder Point = (10 × 21) + 70 = 280 units

Product B: Spiky Seller (Trending Earrings)

• Averages 5 units/day
• But swings between 0 and 25 units depending on social media activity
• Lead time: 7 days (local supplier)
• Safety stock needs to cover those spikes: (25 - 5) × 2 = 40 units

Reorder Point = (5 × 7) + 40 = 75 units

Notice how the trending product needs relatively more safety stock, even though it sells less on average. Variability matters.

Product C: New Product (Just Launched Mug)

• Only 2 weeks of sales data
• Sold 28 units total (2 units/day average)
• Lead time: 14 days
• No max data yet, so use 2 weeks safety stock = 28 units

Reorder Point = (2 × 14) + 28 = 56 units

For new products, err on the side of more safety stock until you understand the demand pattern. Running out of a hot new product is worse than having a bit extra.

Common Mistakes (And How to Avoid Them)

Mistake 1: Using Overall Store Averages

Your store's total sales velocity doesn't help you reorder individual products. Each SKU needs its own calculation based on its own demand pattern.

A store selling 100 units/day might have one product selling 50/day and another selling 1/day. They need very different reorder points.

Mistake 2: Ignoring Lead Time Variability

Suppliers are optimists. If they say "5-7 days," plan for 7 (or 10, if they've missed deadlines before). One late shipment during a busy period can cost you thousands in lost sales.

Track your actual lead times. Keep a simple log of when you ordered and when stock arrived. After a few orders, you'll have real data instead of supplier promises.

Mistake 3: Setting It Once and Forgetting It

Reorder points aren't set-and-forget. Your demand changes seasonally. Suppliers change their processes. New products mature.

Review your reorder points quarterly, or whenever something significant changes (new supplier, big marketing push, seasonal shift).

Mistake 4: Not Accounting for Order Frequency

The reorder point tells you when to order. It doesn't tell you how much to order.

If your reorder point is 56 units and you order 100 units, you'll hit the reorder point at different times than if you order 200 units. Both work, but your inventory patterns will look different. Larger orders mean less frequent ordering; smaller orders mean more flexibility but more admin.

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Tired of recalculating reorder points by hand? QuikStock's free reorder plan generator does the math for every product at once — paste in your stock, recent sales, and supplier lead times, and get a ranked buying list. Try the free tool →

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What About Shopify's Built-In Low Stock Alerts?

Shopify lets you set a "low stock" threshold per product. When inventory drops below that number, you get an alert.

This is basically a manual reorder point. The problem? You have to calculate and set it yourself, for every product. And update it when things change. And remember to actually check those alerts.

If you're using Stocky (Shopify's inventory app), it can calculate reorder points automatically. It pulls your sales data and lead times to suggest when to reorder. Worth using if you have the Shopify plan that includes it.

Third-party apps like Inventory Planner, Fabrikatör, or Skubana offer more sophisticated forecasting. They factor in seasonality, trends, and promotions. Useful if your demand is complex.

But you don't need fancy software to get started. A spreadsheet with the formula above works for most stores under 100 SKUs. The important thing is having a system, not necessarily the most advanced one.

Setting Up a Simple Reorder Point Tracker

Here's a practical approach that works without any apps:

1. Create a spreadsheet with these columns:

• Product name/SKU
• Average daily sales (update monthly)
• Lead time in days
• Safety stock (in units)
• Reorder point (calculated)
• Current inventory (pull weekly from Shopify)

2. Add a "Need to Order" column: Formula: =IF(Current Inventory <= Reorder Point, "ORDER", "")

3. Check it weekly: Export your current inventory from Shopify (Products → Export), paste into your tracker, and look for "ORDER" flags.

It's not automated, but it's systematic. Takes 10 minutes a week and beats checking everything by memory.

Edge Cases: When the Standard Formula Doesn't Fit

Pre-Orders and Made-to-Order Products

If customers can order before you have stock (pre-orders), or you manufacture on demand, the formula changes. Your "lead time" becomes the time from customer order to delivery, and you're managing customer expectations rather than inventory levels.

Highly Seasonal Products

For products with dramatic seasonal swings (holiday decorations, summer gear), calculate separate reorder points for peak and off-peak seasons. Using an annual average will leave you short in December and overstocked in February.

Products with Minimum Order Quantities

If your supplier requires minimum orders of 500 units but your reorder point is 50, you'll need to think differently. Your reorder point still tells you when you'd ideally reorder, but you'll be placing fewer, larger orders and carrying more inventory as a result.

Kits and Bundles

If you sell a bundle of three products, the bundle's reorder point depends on all three component products. Your bundle stock is limited by whichever component runs out first. Track components separately and factor bundle demand into each component's velocity.

The Reorder Point Formula: Quick Reference

Basic Formula:

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

Safety Stock Formula:

Safety Stock = (Max Daily Sales - Avg Daily Sales) × (Max Lead Time - Avg Lead Time)

Quick Safety Stock Estimate:

Safety Stock = Average Daily Sales × 7 (one week buffer)

Where to find your numbers in Shopify:

• Average daily sales: Analytics → Reports → Sales by product
• Current inventory: Products → Export (or Analytics → Reports → Inventory at end of month)
• Lead time: Your supplier + your receiving process

Putting It Into Practice

Calculating reorder points isn't hard. The formula is middle-school math. The hard part is doing it consistently—across all your products, accounting for changes, and actually ordering when the numbers say to.

Here's how to start:

1. Pick your top 10 products by revenue. These are where stockouts hurt most.
2. Calculate reorder points for each. Use the formulas above with real data from your Shopify reports.
3. Set up a tracking system. Spreadsheet, app, or even a whiteboard—just something you'll actually check.
4. Review monthly. Update your average daily sales numbers and adjust safety stock as you learn your patterns.

You don't need to do all 500 SKUs on day one. Start with what matters most, build the habit, then expand.

The merchants who consistently avoid stockouts aren't smarter than you. They just have a system. Now you do too.

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Want reorder points calculated for every product at once? Drop a CSV into the free QuikStock reorder plan generator — get a ranked buying list grouped by supplier, with suggested order quantities and estimated cost. Generate your reorder plan →