About this tool
Make the result useful—not just precise-looking
Translate daily unit sales and supplier timing into an actionable reorder threshold. The calculator can use safety days plus optional extra safety units for a transparent buffer.
How to use it
- Enter average daily sales, lead time, and safety days.
- Add current stock, incoming stock, extra safety units, and target cover.
- Calculate the reorder point and suggested units to order.
Useful for
- Planning a purchase order
- Reviewing stockout risk after sales accelerate
- Setting a simple replenishment alert
Assumptions
- Demand and lead time are constant averages.
- Incoming stock arrives before the planning horizon ends.
- Suggested order quantity targets lead time plus safety and target cover.
Limitations
- The model excludes demand variability, service levels, supplier minimums, and order calendars.
- Fractional demand is rounded up to whole units for reorder decisions.
Common questions
Frequently asked questions
What is a reorder point?
It is the inventory position at which replenishment should be triggered: expected lead-time demand plus safety stock.
What is inventory position?
Here it means current on-hand units plus entered incoming units. Backorders and reserved stock are not included.
Why round units up?
Products are usually ordered in whole units, and rounding down would understate the threshold.