Setting a store-wide safety stock percentage: where to start
A safety stock percentage is a single store-wide setting that raises every SKU's reorder point by a share of its lead-time demand, so items that sell in bursts do not run out before an average-based number is reached. Restoc is built to take that one percentage, apply it inside the reorder point calculation, and show the units it adds per SKU.
What a store-wide percentage actually sets
A reorder point built from sales velocity and lead time covers average demand across the days you wait for a supplier. Average is the problem. Items that sell in bursts, a weekend spike, a creator mention, a wholesale order, empty the shelf before an average-based number is reached, and the alert arrives after the damage.
A safety stock percentage is the cheap correction. You set one figure, the engine applies it to every tracked SKU, and each reorder point rises by that share of its own lead-time demand. A SKU selling 4 a day on a 14-day lead time has 56 units of lead-time cover; at 20 percent it reorders at 67 instead of 56.
The trade-off, stated plainly
- Too low and the buffer does nothing for the SKUs that actually hurt when they go.
- Too high and you reorder earlier on everything, which means more cash parked on shelves and alerts that fire before you need them.
- One number for the store is the point: a 2,000 SKU catalogue does not need 2,000 separate judgement calls before the numbers are useful.
What a percentage buys on a 14-day lead time
| Safety stock percentage | Extra days of cover | The kind of SKU it suits |
|---|---|---|
| 0% | None | Steady sellers where a late order is easy to absorb |
| 10% | About 1.4 days | Predictable demand, a supplier who ships when they say |
| 20% | About 2.8 days | A sensible starting point when sales come in bursts |
| 30% | About 4.2 days | Suppliers who slip, or demand you cannot read yet |
| 50% | 7 days | The SKUs you refuse to run out of, paid for in shelf cash |
Questions
What percentage should I start with?
There is no universal right number, and anyone quoting one has not met your supplier. The useful way in is to pick a figure that buys back the slip you actually see: if a two-week supplier is typically a few days late, that is roughly 20 percent of lead-time demand. Set it, run a couple of order cycles, then look at which SKUs still cut it fine and raise the number. Moving up on evidence costs less than guessing high on day one and tying cash into every SKU you stock.
How is a percentage different from a safety stock formula?
A formula sizes a buffer from the variability in demand and lead time, usually per SKU, and it needs enough clean history to measure that variability. A percentage skips the statistics and scales the buffer to each SKU's own lead-time demand, so a fast mover gets more units than a slow one from the same setting. It is less precise and far quicker to operate. Our glossary page on safety stock walks through the sizing methods if you want the longer version.
Where does the percentage sit in the reorder point math?
The reorder point starts as average daily sales, taken from your chosen velocity window of 7, 14 or 30 days, multiplied by the lead time you enter for that SKU. The safety stock percentage is applied on top of that lead-time demand, and the result is the number each SKU is watched against. When stock crosses it, the alert fires by email, and on Growth and Pro by Slack webhook as well. Nothing else in the calculation changes, which is why you can raise or lower the percentage and see exactly what moved.
Can I set a different percentage for one SKU?
Not today. The safety stock percentage is store-wide: one setting, applied to every tracked SKU. Where per-SKU difference does live is lead time, which you enter per SKU, and on Pro the sales velocity window can be overridden per SKU too. If one supplier is the reason you want a bigger buffer, the honest lever is that supplier's lead time rather than a blanket increase across the catalogue.
Does a bigger buffer just mean more cash sitting on the shelf?
Yes, and that is the real cost of the setting. Every point you add pulls the reorder date earlier, so on average you hold more units of everything for longer. The question is not whether the buffer costs money, it is whether the SKUs it protects are worth more than the cash it parks. Our page on inventory carrying cost works through how to put a figure on the holding side so the comparison is not purely instinct.
How do I tell whether the number is right?
Watch two things over a few order cycles. First, the SKUs that still went to zero or came close, which means the buffer was too thin for how they sell. Second, the SKUs where stock on hand never dipped near the reorder point, which means you ordered earlier than you needed to. The weekly reorder report lists what crossed and the suggested order quantity, and the safety stock column shows the units the percentage contributed, so the evidence for raising or lowering it is on the same screen.
What if my store has barely any sales history yet?
A percentage of a shaky velocity figure is still shaky. On a newly connected store the velocity window has little to average, so reorder points start low and the buffer scales down with them. Give the sync time to build history before you tune the percentage hard, and lean on the lead times you already know from your suppliers in the meantime. There is a separate page on what the numbers show in the first days after a store connects.
Which plan includes the safety stock setting?
It is part of the reorder point calculation, which every plan carries: Starter at $29 a month for up to 200 tracked SKUs, Growth at $59 for up to 1,000, Pro at $99 for up to 2,000, each with a 60-day free trial and yearly billing at ten months' price. Growth adds Slack alerts alongside email. Pro adds the per-SKU velocity window override. The safety stock percentage itself stays store-wide on all three.