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Quick answer
What does the Inventory reorder point calculate?
At what stock level should a new order be placed? This calculator uses average units sold per day, supplier lead time, and safety-stock days to estimate stock level that triggers an order immediately in your browser.
With the values currently entered, the result is 306 units — reorder point. It also shows expected lead-time demand, and safety stock.
How to use the Inventory reorder point
- Replace the example values with your own numbers.
- Review the result and supporting figures as they update automatically.
- Check the formula and assumptions before using the estimate for a decision.
Inputs used
- Average units sold per day — entered in units
- Supplier lead time — entered in days
- Safety-stock days — entered in days
Inventory reorder point formula
Daily sales × (supplier lead time + safety-stock days)
Assumptions
- Average demand remains stable.
- Lead time is measured in the same selling days as demand.
Practical guide
Inventory reorder point example and edge cases
At what stock level should a new order be placed? Let's use a concrete example, then look at the assumptions that can move the answer.
Example: A practical inventory reorder point scenario
For this example, use average units sold per day of 18 units, supplier lead time of 12 days, and safety-stock days of 5 days. These are starting values, so replace them with numbers that match your situation.
- Average units sold per day
- 18 units
- Supplier lead time
- 12 days
- Safety-stock days
- 5 days
Calculated result306 unitsreorder point
Start with reorder point. Then check expected lead-time demand, and safety stock to understand what sits behind the main result.
Example results use the default display profile. The calculator above follows your selected country and units.
How to read the result
- Read the main result first. The supporting figures for expected lead-time demand, and safety stock explain how the estimate is built.
- The method is Daily sales × (supplier lead time + safety-stock days). Keep the units consistent and use values from the same time period.
Edge cases worth checking
When average units sold per day is unusual
Average demand remains stable. Double-check this input before relying on the result.
When safety-stock days is uncertain
Lead time is measured in the same selling days as demand. Run a lower and higher value to see a useful range.
What changes the result most
Average units sold per day
Use the count you expect in real life. Round up when a partial units cannot be purchased or used.
Supplier lead time
Keep supplier lead time on the same time basis as the other inputs. Monthly and annual values are easy to mix up.
Safety-stock days
Keep safety-stock days on the same time basis as the other inputs. Monthly and annual values are easy to mix up.
Try a different scenario
Small changes show whether the answer is stable or sensitive.
Average units sold per day: 10% lower
16 units272 unitsreorder point
Average units sold per day: 10% higher
20 units340 unitsreorder point
Supplier lead time: 10% higher
13 days324 unitsreorder point
Common mistakes
Check average units sold per day
Average demand remains stable. Make sure this matches the number you enter.
Keep safety-stock days consistent
Lead time is measured in the same selling days as demand. Use the same units and time period throughout the calculation.
Do not rely on one inventory reorder point scenario
Run a cautious case and an optimistic case. The range is often more useful than one exact-looking number.
Use this result well
At what stock level should a new order be placed?
It does not replace a quote, contract, accountant, or local employment guidance.