Free Operations tool
Inventory Reorder Calculator
Know when to place your next order: combine expected demand during lead time with a buffer for uncertainty.
Your result
Use the example or enter your figures, then calculate.
Use conservative estimates when demand or delivery times vary. This does not model stock already on order or batch quantities.
How it works
Reorder point = average daily unit sales × supplier lead time in days + safety stock. Days remaining = (stock on hand − safety stock) ÷ average daily sales.
Common questions
What is safety stock?
Extra units held to absorb unexpected demand or supplier delays.
What if demand is zero?
A reorder point still reflects safety stock, but days of cover cannot be estimated.
Related free tools
Need something built for your business?
The public tool catalogue is free. For a custom website or workflow, tell us what you need.
Ask about custom work