Safety Stock Calculator

How to use the Safety Stock Calculator

Estimate a buffer using the maximum-demand and maximum-lead-time method. Enter daily demand values and lead times in days on a consistent basis.

Formula

Safety stock = max(0, round up(maximum demand × maximum lead time − average demand × average lead time)).

Worked example

Maximum demand of 30 units/day and maximum lead time of 10 days, versus averages of 20 units/day and 7 days, give 300 − 140 = 160 buffer units.

Interpretation and limitations

This heuristic combines extremes and does not target a statistical service level. The tool floors negative estimates at zero, so validate that maximum values are at least as high as their corresponding averages.

Safety Stock questions

Does this guarantee no stockouts?

No. Future demand and lead time can exceed historical assumptions.

Why can the buffer be large?

Maximum demand and maximum lead time are assumed to occur together. That can be conservative if those extremes rarely coincide.

Continue your calculation

For the next step, use the Reorder Point Calculator or the Stockout Cost Calculator. Review each tool’s input definitions before carrying a result into another calculation.

Frequently asked questions

Is this calculator free?

Yes. It runs in your browser and does not require an account.

How should I use the result?

Use the result as a planning estimate and verify business-critical decisions against your source records.