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Reorder point calculator

Find the inventory level at which to reorder, from demand, lead time and safety stock.

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Need Reorder point (units)? The Reorder point calculator derives it from Average daily demand (units), Lead time (days), Safety stock (units) in one step. For instance, with Average daily demand (units) = 50, Lead time (days) = 7 and Safety stock (units) = 100 it returns Reorder point (units) = 450.

How to use it

  1. Enter your values: Average daily demand (units), Lead time (days), Safety stock (units).
  2. Read the result instantly: Reorder point (units).

Frequently asked questions

What does the Reorder point calculator actually compute?

It takes Average daily demand (units), Lead time (days) and Safety stock (units) and derives Reorder point (units) from them. The calculation is live as you type, so the result updates on every change.

What information do I need to provide?

3 values: Average daily demand (units), Lead time (days) and Safety stock (units). Nothing else is required — no account, no file upload.

Can you show a worked example?

With Average daily demand (units) = 50, Lead time (days) = 7 and Safety stock (units) = 100, the calculator returns Reorder point (units) = 450. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

What happens if I enter larger values?

It moves a lot. Using Average daily demand (units) = 100, Lead time (days) = 14 and Safety stock (units) = 200 instead, Reorder point (units) goes from 450 to 1,600 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Average daily demand (units) = 25, Lead time (days) = 4 and Safety stock (units) = 50, Reorder point (units) comes out at 150. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Running the week: issuing an invoice or a quote, knowing what is in stock and what to reorder, and seeing whether cash covers what is due.

What is the most common mistake?

Reading profit as cash. A profitable month with sixty-day payment terms can still leave the account empty — the two numbers answer different questions.

What is the difference between the Reorder point calculator and the Safety stock calculator?

Both return Reorder point (units). What differs is what they ask for: this one wants Average daily demand (units) and Safety stock (units), the Safety stock calculator wants Service level (%) and Average daily demand. Use whichever matches the numbers you already have.

Is there a tool for the next step?

Takt time calculator is the closest one after this: Compute the takt time — the pace of production needed to meet demand.

What else is worth having open alongside it?

Average collection period calculator and Inventory period calculator — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
ExplainerGMROI: the Inventory Number That Outranks MarginGross margin return on inventory investment divides gross margin by the cash tied up in stock. It exists because margin alone ranks products wrongly: a 60% margin turning twice a year loses to a 25% margin turning twelve times.ExplainerThe EOQ Square-Root Formula, and Where It Stops Being TrueEOQ = √(2DS/H) balances ordering cost against holding cost. Its most useful property is how flat the cost curve is around the optimum — and its four failure modes are quantity discounts, lumpy demand, a finite replenishment rate, and the two inputs nobody can measure.ExplainerProcess Capability: Cp, Cpk and What Six Sigma Actually ClaimsCp compares the spec width to the process spread; Cpk penalises being off-centre. A process can have an excellent Cp and still make scrap — here is the case, with defect rates computed from the normal distribution rather than read off a table.ExplainerThe Cash Conversion Cycle: the Number That Explains Why You Are Out of CashCCC = DIO + DSO − DPO. It is the number of days your cash is out of your hands, and it is the reason a profitable, growing business runs out of money. Worked end to end, with the negative-cycle case that makes suppliers your cheapest lender.ExplainerTakt Time, Cycle Time and Lead Time Are Three Different ClocksTakt is demand, cycle time is capability, lead time is what the customer experiences. Confusing them is the most common failure in a first improvement project — and Little's Law is the bridge from one to the next.ComparisonFIFO vs LIFO: What Actually Changes, and What Does NotFIFO and LIFO are assumptions about which cost you attach to a sale, not about which box leaves the warehouse. Worked through identical purchases and sales, they move cost of sales, inventory, profit and tax — but operating cash before tax is identical to the cent.