What is safety stock?

Safety stock is the extra stock you keep on top of what you expect to sell, as a cushion against late deliveries or a sudden rise in sales.

How to work it out

There are statistical formulas, but a simple one works for most small stores:

Safety stock = (highest daily sales − average daily sales) × lead time in days

That covers a stretch where you sell at your busiest pace for the whole wait. Some stores simply keep a fixed number of days of sales as a buffer, for example one extra week.

WooCommerce doesn't have a safety stock field. It shows up inside your reorder point: reorder point = average daily sales × lead time + safety stock. You can find your daily sales from Analytics › Products, picking a date range and dividing Items sold by the number of days. Setting the result as the product's low-stock threshold makes WooCommerce's low-stock email work as a reorder reminder.

A worked example

Say a mug sells 5 a day on average, but on busy days it sells 8. Your supplier takes 10 days.

• Safety stock: (8 − 5) × 10 = 30 mugs
• Reorder point: 5 × 10 + 30 = 80 mugs

Why it matters

Safety stock is the trade-off between running out and tying cash up in inventory. Too little and a late shipment means lost sales. Too much and money sits on shelves. Keep more for products with unreliable suppliers or long lead times, and less for those you can restock quickly. The guide on setting reorder points shows how it fits together, and what running out of stock costs helps you decide how much cushion is worth paying for.