Mini-App · Inventory
Reorder Point and 30-Day Order Quantity Calculator
For small retailers and online sellers who need a clear signal for when to restock. Enter an item's average daily sales, your supplier's lead time in days, and how many days of safety stock you want.
You get safety stock in units, expected sales during lead time, the reorder point, and how many units to order to cover the next 30 days (or any period you choose).
Results update as you type. Free to use.
Reorder point
120 units
Order quantity
360 units
- Safety stock
- 36 units
- Sales during lead time
- 84 units
How to use it
- 1Type the item's average daily sales in units, the supplier's lead time in days, and how many days of safety stock you want to keep.
- 2Leave 'Days to cover' at 30, or change it if you order for a different period.
- 3Reorder point: when stock on hand falls to this many units, place an order. It equals lead-time demand plus safety stock.
- 4Order quantity: the number of units to order to cover the chosen number of days of sales, rounded up to whole units.
Common questions
How is the reorder point calculated?
Sales during lead time is average daily sales times the supplier lead time in days. Safety stock is average daily sales times your safety stock days. The reorder point is those two numbers added together.
Do I need to upload a spreadsheet or sales file?
No. This is a calculator, so you just type four numbers. To get average daily sales, divide the units sold over the last 30 or 90 days by that number of days.
How is the order quantity worked out?
It's average daily sales times the 'Days to cover' value, which defaults to 30, rounded up to whole units. Change 'Days to cover' if you order weekly, every 60 days, or on some other schedule.
Does it cost anything, and is my data kept private?
Calculators are free, with no credits needed. You only enter a few numbers, not your sales records or product files.