Free Shopify Inventory Reorder Point Calculator
Calculate when to reorder inventory, estimate safety stock, see how many days of stock remain, and calculate a suggested reorder quantity for your Shopify products.
Inventory Details
Enter your product sales and inventory data below.
What Is a Shopify Inventory Reorder Point Calculator?
A Shopify inventory reorder point calculator helps merchants estimate the inventory level at which they should consider placing a new stock order.
Instead of waiting until inventory is almost empty, the calculation uses sales velocity, supplier lead time and safety stock to estimate a reorder threshold.
What Does This Inventory Calculator Calculate?
How Is Average Daily Sales Calculated?
This calculator uses the number of units sold during the last 30 days to estimate average daily sales.
Example: If your Shopify store sold 300 units during the last 30 days, average daily sales would be approximately 10 units per day.
What Is a Reorder Point?
A reorder point is the inventory level at which a business considers placing another order with its supplier.
The objective is to order early enough for new inventory to arrive before existing stock is depleted.
How Is Lead-Time Demand Calculated?
Lead-time demand estimates how many units may be sold while waiting for the supplier to deliver replenishment inventory.
What Is Safety Stock?
Safety stock is additional inventory held as a buffer against unexpected demand, supplier delays or other inventory uncertainty.
This calculator uses safety-stock days to create a simple buffer based on average daily sales.
Shopify Inventory Reorder Point Example
Assume a Shopify product sells 300 units every 30 days. That equals approximately 10 units per day.
The supplier requires 14 days to deliver new stock and the merchant wants 7 days of safety stock.
Lead-time demand = 10 × 14 = 140 units.
Safety stock = 10 × 7 = 70 units.
Reorder point = 140 + 70 = 210 units.
Reorder Point vs Safety Stock
| Metric | Purpose | Formula Used Here |
|---|---|---|
| Average Daily Sales | Estimates normal daily product demand. | 30-Day Units Sold ÷ 30 |
| Lead-Time Demand | Estimates demand while waiting for replenishment. | Daily Sales × Lead Time |
| Safety Stock | Adds an inventory buffer. | Daily Sales × Safety Stock Days |
| Reorder Point | Estimates when replenishment should be triggered. | Lead-Time Demand + Safety Stock |
How Are Days of Inventory Remaining Calculated?
Days of inventory remaining estimates how long current inventory could last if the recent average sales rate continues.
This is an estimate rather than a demand forecast. Actual daily sales can rise or fall because of seasonality, promotions, advertising, product trends and other factors.
How Is Suggested Reorder Quantity Calculated?
The calculator uses your target stock coverage to estimate a target inventory level.
It then compares that target with current and incoming inventory.
If current and incoming inventory already meet or exceed the target, the suggested reorder quantity is displayed as zero.
Why Inventory Reorder Planning Matters
Inventory shortages can interrupt sales, while excessive inventory can tie up cash in stock that may take a long time to sell.
A structured reorder process can help merchants make replenishment decisions using demand, supplier lead time and inventory coverage instead of relying only on guesswork.
How to Use This Shopify Inventory Calculator
1. Enter Current Inventory
Enter the number of units currently available for the product.
2. Enter Units Sold During the Last 30 Days
Use recent sales volume to estimate average daily demand.
3. Enter Supplier Lead Time
Add the approximate number of days between placing an order and receiving the inventory.
4. Choose Safety Stock Days
Enter the number of additional days of demand you want to hold as a simple inventory buffer.
5. Add Incoming Inventory
If stock is already on order, enter those units so the suggested reorder quantity can account for them.
6. Set Target Stock Coverage
Enter how many days of estimated demand you would like your inventory to cover after replenishment.
What Can Affect Your Reorder Point?
Who Can Use This Calculator?
Frequently Asked Questions
What is an inventory reorder point?
A reorder point is an inventory threshold used to determine when a business should consider ordering more stock before existing inventory runs out.
How do you calculate a reorder point?
A common basic approach is to add expected demand during supplier lead time to safety stock. This calculator uses average daily sales multiplied by lead time, plus a safety-stock buffer.
What is safety stock?
Safety stock is additional inventory held as a buffer against unexpected demand, supplier delays or other uncertainty.
How much safety stock should I keep?
There is no single amount suitable for every product. Appropriate safety stock depends on demand variability, supplier reliability, lead times, seasonality, stockout costs and the business's inventory strategy.
How are average daily sales calculated?
This calculator divides the units sold during the last 30 days by 30. For products with highly seasonal or volatile demand, a more detailed forecasting method may be appropriate.
What is supplier lead time?
Supplier lead time is the approximate time between placing a replenishment order and having the inventory available for sale.
Can Shopify merchants use this calculator?
Yes. Shopify merchants can use their recent product sales and inventory information to estimate reorder points, safety stock and inventory coverage.
Does incoming inventory affect reorder quantity?
Yes. The suggested reorder quantity in this calculator subtracts both current inventory and entered incoming inventory from the estimated target stock level.
Does this calculator predict future demand?
No. It uses recent average sales as a simplified demand assumption. It does not predict seasonality, promotions, trends or future changes in customer demand.
