Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Reorder at this stock level
1,470
Safety stock
525
Economic order quantity
1,187
Orders per year
13.8
Days between orders
26.4
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter average units sold per day.
- 2Enter supplier lead time (days).
- 3Enter peak units per day.
- 4Enter cost to place an order ($).
- 5Enter annual holding cost per unit ($).
- 6Read your reorder at this stock level on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
Reorder point covers demand during the lead time plus a buffer for the weeks when demand spikes or the supplier slips. Getting this wrong is the difference between a stockout and dead capital.
Worked example
Using the values the calculator loads with:
Inputs
- Average units sold per day: 45
- Supplier lead time: 21 days
- Peak units per day: 70
- Cost to place an order: 180 $
- Annual holding cost per unit: 4.2 $
Results
- Reorder at this stock level: 1,470
- Safety stock: 525
- Economic order quantity: 1,187
- Orders per year: 13.8
- Days between orders: 26.4
What each field means
Inputs
- Average units sold per day
- The average units sold per day used in the calculation. Starts at 45 so you have a working example on load.
- Supplier lead time (days)
- The supplier lead time used in the calculation, measured in days. Starts at 21 days so you have a working example on load.
- Peak units per day
- The peak units per day used in the calculation. Starts at 70 so you have a working example on load.
- Cost to place an order ($)
- The cost to place an order used in the calculation, measured in $. Starts at 180 $ so you have a working example on load.
- Annual holding cost per unit ($)
- The annual holding cost per unit used in the calculation, measured in $. Starts at 4.2 $ so you have a working example on load.
Results
- Reorder at this stock level
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Safety stock
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Economic order quantity
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Orders per year
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Days between orders
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the reorder point calculator work?
Reorder point covers demand during the lead time plus a buffer for the weeks when demand spikes or the supplier slips. Getting this wrong is the difference between a stockout and dead capital. The underlying maths is: Reorder point = (Daily demand × Lead time) + Safety stock. EOQ = √(2DS ÷ H).
What do I need to enter?
5 values: average units sold per day, supplier lead time, peak units per day, cost to place an order, and annual holding cost per unit. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the reorder at this stock level result mean?
It is returned as a whole number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Estimates assume standard, average conditions — local rules, pricing, and materials vary.
Who is this tool for?
It's built for anyone doing everyday planning maths — a quick estimate that would otherwise need four browser tabs and a calculator app.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Reorder Point Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/reorder-point
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/reorder-point" target="_blank" rel="noopener">Reorder Point Calculator — RevenueLab</a> (2026).</p>
Source: [Reorder Point Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/reorder-point) (2026).