Reorder Point Calculator
Calculate the optimal reorder point for your e-commerce inventory using the formula: Reorder Point = (Average Daily Sales x Lead Time) + Safety Stock
How to Calculate Reorder Point
The reorder point determines when to place a new order to prevent stockouts:
- Average Daily Sales: Average number of units sold per day
- Lead Time: Number of days between placing an order and receiving it
- Safety Stock: Extra inventory to account for unexpected demand or delays
- Reorder Point: Inventory level that triggers a new purchase order
Calculate Reorder Point
Reorder Point Visualization
Inventory Status
Reorder Analysis
Inventory Recommendations
Your reorder point of 225 units will help prevent stockouts with 50 units of safety stock.
- Place orders when inventory reaches 225 units
- Monitor sales velocity for adjustments
- Review lead times with suppliers regularly
- Adjust safety stock based on seasonal demand
Understanding Reorder Points
What is a Reorder Point?
A reorder point is the specific inventory level at which a new purchase order should be placed to replenish stock before it runs out. It's calculated to balance carrying costs with stockout risks.
The Reorder Point Formula
The standard formula for calculating reorder point is:
This formula accounts for expected demand during the lead time plus extra buffer for uncertainties.
Key Reorder Point Rules
- Reorder points should be recalculated regularly as demand patterns change
- Safety stock should reflect variability in demand and supply
- Lead time must account for shipping, customs, and processing delays
- Different products may require different safety stock levels
- Seasonal items need adjusted calculations for peak periods
Reorder Point Quiz
Question 1: Basic Calculation
If a product has average daily sales of 10 units, a lead time of 5 days, and safety stock of 20 units, what is the reorder point?
Using the formula: Reorder Point = (Average Daily Sales × Lead Time) + Safety Stock
Reorder Point = (10 × 5) + 20 = 50 + 20 = 70 units
The correct answer is c) 70 units.
This question tests understanding of the basic reorder point formula. Remember that safety stock is added after calculating expected demand during lead time.
Reorder Point: The specific inventory level that triggers a new purchase order to replenish stock before it runs out.
Always calculate expected demand during lead time first (average daily sales × lead time), then add safety stock. Don't multiply all three values together.
Question 2: Real-World Scenario
A retailer sells an average of 30 units per day of a popular item. The supplier takes 10 days to deliver orders. To account for potential demand spikes, the retailer maintains 100 units of safety stock. At what inventory level should they place a new order?
Scenario Details:
- Average daily sales: 30 units
- Lead time: 10 days
- Safety stock: 100 units
Expected demand during lead time = 30 × 10 = 300 units
Reorder Point = 300 + 100 = 400 units
The retailer should place a new order when inventory reaches 400 units.
For products with highly variable demand, increase safety stock proportionally. For consistent products, a smaller safety stock may suffice.
Q&A
Q: How do I determine the right amount of safety stock for my products?
A: Determining the right safety stock involves balancing carrying costs against stockout risks:
Factors to Consider:
- Demand Variability: Higher variation requires more safety stock
- Lead Time Variability: Unpredictable delivery times need buffer stock
- Service Level Target: Higher target (95% vs 85%) requires more safety stock
- Product Value: High-value items may need less safety stock
- Seasonality: Adjust safety stock for predictable demand fluctuations
Basic Calculation:
Safety Stock = Z × σ × √(LT)
Where Z = service factor, σ = standard deviation of demand, LT = lead time
For most e-commerce businesses, starting with 10-30% of expected lead time demand as safety stock is reasonable, then adjusting based on actual performance.
Q: Should I use the same reorder point for all my products?
A: No, you should calculate separate reorder points for each product based on its specific characteristics:
Product Categories:
- Fast-moving items: Higher reorder points, frequent reordering
- Slow-moving items: Lower reorder points, less frequent orders
- Seasonal items: Adjust based on seasonal demand patterns
- High-value items: Lower safety stock to reduce carrying costs
- Perishable items: Lower reorder points to minimize waste
ABC Analysis Approach:
- A-items (high value): More precise calculations, lower safety stock
- B-items (medium value): Standard approach
- C-items (low value): Higher safety stock, simpler calculations
Customizing reorder points by product ensures optimal inventory investment across your entire catalog.