---
title: "What is safety stock? Formula and example | Product Metrics"
description: "Safety stock is the extra stock held to cover demand or supply that runs above plan. See one common formula, a worked example and its link to reorder points."
canonical: "https://www.productmetrics.io/glossary/safety-stock"
pageType: article
language: en
publisher: "Product Metrics"
author: "Berend Vrakking"
datePublished: 2026-10-07
dateModified: 2026-10-07
---

> Content index: https://www.productmetrics.io/llms.txt

# Safety stock

Safety stock is the extra stock you hold beyond expected demand, so a sudden rise in sales or a late delivery does not leave you out of stock.

## Formula

`Safety stock = days of extra cover × average daily demand`

This is one common method, not the only one. Others use the spread of demand and of lead time, or the gap between the highest and the average daily sales. The days of cover are your choice.

## Example

Worked example, three products:

| Product | Average daily demand | Days of extra cover | Safety stock |
| --- | --- | --- | --- |
| Trail Runner 2 | 20 units | 5 days | 100 units |
| Winter Boot | 4 units | 7 days | 28 units |
| Everyday Sock | 60 units | 3 days | 180 units |

Each product gets its own cover, so Trail Runner 2 holds 20 × 5 = 100 units of safety stock. This stock is not for the expected demand. It sits untouched until demand or delivery goes off plan. Illustrative data.

## For one product, and for an account

A product whose sales swing from day to day, or whose supplier is often late, needs more cover than a steady product with a reliable supplier. One number of days for the whole shop leaves some products short and ties up money in others.

Inventory Insights calls this the safety buffer. It uses the buffer, with projected demand and the supplier lead time, to work out a reorder date for each product.

## Common mistake

Picking a formula and never checking it against what happened. How much demand and lead time vary for a product decides which method suits it, and its stockouts and untouched buffers tell you whether you chose well.

## Questions

### What is another name for safety stock?

Safety stock is also called buffer stock. Inventory Insights uses the term safety buffer for the same idea: the stock you never want to dip below.

### What is a good safety stock level?

Enough to cover the demand and delivery variation you actually see for that product, and no more, so money does not sit in stock that never sells. Your past stockouts and the products that gathered dust on the shelf show which way to move it.

### Is safety stock the same as minimum stock?

Not necessarily. Safety stock is the extra units held against variation. The reorder point is the level that triggers an order, and it includes safety stock. “Minimum stock” is used for different things in different businesses, so check which level a person means.

## Keep reading

- [Reorder point](https://www.productmetrics.io/glossary/reorder-point): Safety stock is added to demand during the lead time.
- [Lead time](https://www.productmetrics.io/glossary/lead-time): A longer lead time leaves more room for demand to run above plan.
- [Stockout](https://www.productmetrics.io/glossary/stockout): The event that safety stock is held to prevent.
- [Inventory Insights](https://www.productmetrics.io/inventory-insights): See the safety buffer in each product’s reorder date.
- [Dead stock inventory](https://www.productmetrics.io/blog/dead-stock-inventory): Where a safety buffer ends and stock that will not sell begins.

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Written by Berend Vrakking, founder of Product Metrics. Last updated 2026-10-07.

HTML version: https://www.productmetrics.io/glossary/safety-stock