Free tool
Reorder point calculator
When should you order more gloves, filters or fixings? Enter how fast you use them and how long a delivery takes. The calculator shows the reorder point, the safety stock and a sensible maximum, with the working.
- Safety stock
- 14
- Suggested maximum
- 112
- Typical order
- 70
7 a day × 4 days = 28, plus 14 safety stock = 42.
In ItemTally, the reorder point is Low-stock alert at and the maximum is Restock to, set per location on the Stock levels page.
How the reorder point works
You need enough stock on the shelf to last while a new delivery is on its way. That's daily usage × lead time. If you use 7 boxes a day and delivery takes 4 days, you need 28 boxes left when you order. On a perfect week.
Safety stock covers the imperfect weeks: a busy day, a late van, a supplier out of
stock. The simple version is a few days of usage. The common formula is
(most used in a day × longest delivery) − (average daily use × average delivery),
which covers the busiest day and the latest delivery happening together.
The maximum (or par level) is the reorder point plus what you use between orders. Order up to it each time, and you won't overfill the shelf or tie up money in stock that sits for months.
Small teams, not warehouses
Formulas such as economic order quantity are built for warehouses with holding costs and bulk discounts. For a store room, a van or a lab shelf, usage × lead time plus a buffer is enough, as long as you look at the numbers again when usage changes.
Questions people ask
What is the reorder point formula?
Reorder point = average daily usage × lead time in days + safety stock. When stock falls to that number, you order.
How do I work out safety stock?
The simple way: a few days of usage as a buffer. The common formula: (highest daily usage × longest lead time) minus (average daily usage × average lead time). It covers a busy week and a late delivery at once.
What's the difference between a reorder point and a par level?
The reorder point is when to order. A par level, or maximum, is what a full shelf holds. The order quantity is the par level minus what's left.
How often should I recalculate?
Whenever usage changes noticeably, and at least twice a year. Seasonal items need a different number in their busy months.
Where do I find my daily usage?
From delivery records or a usage log: what you used over the last month or quarter, divided by the number of working days. A consumables tracker with a usage log gives you this.
Let the shelf tell you when it's low.
ItemTally shows anything at or below its minimum on Today, per location.
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