Free Reorder Point Calculator
Calculate when to review replenishment
Reorder point = average daily demand × lead time in days + safety stock. Enter consistent units to estimate a replenishment trigger, then check outstanding orders and committed stock.
What Is a Reorder Point Calculator?
A reorder point calculator estimates when to review a new purchase order using average daily demand, replenishment lead time and safety stock. It answers when to order; an EOQ or replenishment quantity calculation answers how much. Use consistent units and review the assumptions whenever demand or supplier performance changes.
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Reorder point example: check inventory position before ordering
At 20 units per day, seven days of lead time and 40 buffer units, the reorder point is 20 × 7 + 40 = 180 units. This illustrative calculation assumes a consistent planning period and unit of measure.
If on-hand stock is 150, an open supplier order is 80 and unfulfilled commitments are 20, inventory position is 150 + 80 − 20 = 210 units. It exceeds the 180-unit trigger, even though shelf stock alone is lower. Check that the open order will arrive in time; a late order can still leave a shortage.
When should I recalculate my reorder level?
Review after supplier delays, promotions, stockouts or a change in sales mix. Sales recorded during a stockout may understate demand. For weekly ordering, include the review interval in your planning; this continuous-review formula alone does not cover it.
Inventory statistics: context for your stock decisions
The US Census Bureau reported $2,818.8 billion in seasonally adjusted manufacturing and trade inventories for August 2026, up 0.4% from July. The total business inventories-to-sales ratio was 1.33, compared with 1.40 in August 2025.
These are US economy-wide estimates released on 15 October 2026, not small-business targets or results achieved with My Inventory Items. The ratio compares end-of-month inventory with monthly sales; it is different from inventory turnover calculated using cost of goods sold. A national ratio cannot tell you how many units of a particular SKU to order.
Source: US Census Bureau, August 2026 Manufacturing and Trade Inventories and Sales · Checked .
For your own replenishment plan, measure daily demand, actual supplier lead time and available stock by SKU. Compare the buffer with cash, shelf life and storage constraints.
Work through a replenishment analysis · Browse dated inventory research and source context
How to Find Your Reorder Point in 3 Steps
Step 1 — Enter Average Daily Sales
How many units of this product do you sell per day on average? If you sell 30 units a week, your daily sales = 30 ÷ 7 ≈ 4.3 units/day.
Step 2 — Enter Lead Time
Lead time is the number of days it takes from placing a purchase order with your supplier to receiving the stock in your store or warehouse.
Step 3 — Set Safety Stock (Optional)
Safety stock is a buffer for demand or delivery variation. A zero buffer assumes no extra protection; review actual variation and the impact of shortages before choosing it.
Who Uses This Reorder Point Calculator?
Retail Shop Owners
Estimate reorder triggers for each product and review them when seasonal demand or delivery times change.
Warehouse & Store Managers
Set reorder alerts in your inventory system at the calculated ROP for each SKU.
Pharmacy Owners
Keep critical medicines in stock by calculating reorder points based on prescription rates and supplier lead times.
E-commerce Sellers
Prevent out-of-stock listings that hurt search rankings and sales by ordering at the right time.
Frequently Asked Questions
What is a reorder point?
A reorder point (ROP) is a replenishment trigger: average daily demand × lead time + safety stock. Under continuous review, compare the trigger with inventory position (on-hand + on-order − backorders or committed demand, counted once) to avoid duplicate orders. It does not guarantee stock availability.
How do you calculate the reorder point?
Use the reorder point formula: ROP = (Average daily sales × Lead time in days) + Safety stock. Example: you sell 20 units a day, your supplier takes 7 days to deliver and you keep 40 units of safety stock. ROP = (20 × 7) + 40 = 180 units, so place a new order as soon as stock falls to 180.
How do you calculate safety stock for the reorder point?
A common method is Safety stock = (Maximum daily sales × Maximum lead time) − (Average daily sales × Average lead time). If you sell at most 30 units a day, the longest delivery took 10 days, and on average you sell 20 a day with a 7-day lead time, safety stock = 300 − 140 = 160 units.
What is safety stock?
Safety stock is extra inventory held for demand or delivery variation. Size it using your SKU history, desired service level, supplier reliability and holding constraints. A fixed number of weeks is not a universal recommendation.
How do I calculate average daily sales?
Add up total units sold over a period (e.g. 30 days) and divide by the number of days. Example: 900 units sold in 30 days = 30 units/day average.
What is lead time in inventory?
Lead time is the total time from placing a purchase order to receiving the goods. It includes supplier processing time, production (if applicable), shipping, and any customs clearance.
What happens if I go below the reorder point without ordering?
You risk a stockout — running out of inventory entirely. This leads to lost sales, unhappy customers, and potential damage to your business reputation.
Is this reorder point calculator free?
Yes, completely free. No login or account needed.