Reorder point calculator
Know when to reorder and how much: reorder point and safety stock by two methods, plus the order size that keeps ordering and holding costs lowest.
Example numbers. Replace them with yours.
- Reorder point (statistical)
- 273
- Safety stock (statistical)
- 73
- Reorder point (max method)
- 420
- Safety stock (max method)
- 220
- Order quantity (EOQ)
- 624
- Orders per year
- 11.7
What it calculates
The reorder point is the stock level that should trigger a new purchase order: what you sell during the supplier's lead time, plus safety stock for bad days. Safety stock can be set by a simple worst-case rule or statistically from how much demand and lead time vary. EOQ (economic order quantity) balances the cost of placing orders against the cost of holding stock.
How to read the result
The statistical method usually needs less safety stock than the max method for the same protection. A higher service level means fewer stockouts and more cash tied up in stock. EOQ is a starting point: supplier minimums and cash can override it.
Learn the metric:COGS
The formula
Reorder point = Daily sales × lead time + safety stock Safety (max method) = Peak daily × longest lead − daily × lead Safety (statistical) = z × √(lead × σ_demand² + daily² × σ_lead²) EOQ = √(2 × yearly demand × order cost ÷ (unit cost × holding %))
Worked example
Example inputs
- Average units sold per day
- 20
- Supplier lead time
- 10
- Peak units per day
- 30
- Longest lead time
- 14
- Daily demand variation (σ)
- 6
- Lead time variation (σ)
- 2
- Service level
- 95%
- Cost per purchase order
- USD 60
- Unit cost
- USD 9
- Holding cost per year
- 25%
Results
- Reorder point (statistical)
- 273
- Safety stock (statistical)
- 73
- Reorder point (max method)
- 420
- Safety stock (max method)
- 220
- Order quantity (EOQ)
- 624
- Orders per year
- 11.7
What changes the result
Supplier lead time at five values. Every other input stays as in the worked example; the highlighted row is the example.
| Supplier lead time | Reorder point (statistical) | Safety stock (statistical) |
|---|---|---|
| 5 | 169 | 69 |
| 8 | 231 | 71 |
| 10 | 273 | 73 |
| 13 | 335 | 75 |
| 15 | 376 | 76 |
Use your real numbers
Analify reads daily units sold and inventory levels from Shopify and product costs, so your sales rate comes from real orders.
Analify already reads 4 of these 10 inputs live, from Shopify
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Questions
How do I calculate a reorder point?
Daily sales × supplier lead time in days, plus safety stock.
How much safety stock do I need?
Enough to cover demand and lead time being worse than average. The statistical method sizes it for the service level you choose.
What is EOQ?
Economic order quantity: the order size where the cost of placing orders and the cost of holding stock are lowest together.
Do you store what I enter?
No. The calculation runs in your browser and nothing is sent to Analify.
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