---
title: "Excess inventory formula, cost and example | Product Metrics"
description: "Calculate excess inventory per product: stock above forecast demand to the next delivery plus safety stock, at cost, rolled up by category, brand or price band."
canonical: "https://www.productmetrics.io/glossary/excess-inventory"
pageType: article
language: en
publisher: "Product Metrics"
author: "Berend Vrakking"
datePublished: 2026-10-25
dateModified: 2026-10-25
---

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

# Excess inventory

Excess inventory is stock beyond what covers expected demand until your next delivery arrives plus the safety stock you chose to hold.

## Formula

`Capital tied up in excess stock = Σ (excess units × unit cost), where excess units = sellable units on hand − (expected weekly demand × weeks until the next delivery arrives + safety stock), and never below zero`

Value the units at what you paid for them, not at selling price. Count only sellable units, not damaged, quarantined or already allocated to orders, and add a confirmed inbound delivery only if it lands before the coverage date. Keep one demand period throughout, here units per week, from a forecast that fits the product’s season and lifecycle: a recent average overstates excess just before a peak and understates it after demand has fallen. State the safety stock and the review date, so someone else can reproduce the figure.

## Example

Worked example, demand per week, value at cost:

| Product | On hand | Cover needed | Unit cost | Excess units | Excess at cost |
| --- | --- | --- | --- | --- | --- |
| Trail Runner 2 (shoes, Northpeak, €139.99) | 300 | 220 (40 × 4 + 60) | €56.00 | 80 units | €4,480.00 |
| Winter Boot (shoes, Fjell, €159.99) | 400 | 60 (5 × 8 + 20) | €64.00 | 340 units | €21,760.00 |
| Rain Jacket (clothing, Northpeak, €89.99) | 180 | 200 (25 × 6 + 50) | €36.00 | 0 units (20 short) | €0.00 |
| Everyday Sock (clothing, Fjell, €12.99) | 1,200 | 450 (150 × 2 + 150) | €3.00 | 750 units | €2,250.00 |
| Category: shoes | 700 | 280 | Mixed | 420 units | €26,240.00 |
| Brand: Fjell | 1,600 | 510 | Mixed | 1,090 units | €24,010.00 |
| Price range: under €100 | 1,380 | 650 | Mixed | 750 units | €2,250.00 |
| All four products | 2,080 | 930 | Mixed | 1,170 units | €28,490.00 |

Each roll-up adds up the product rows. Rain Jacket’s shortfall does not cancel excess elsewhere, so the total is 1,170 excess units, not 2,080 − 930 = 1,150. At selling price those units come to €75,338.30; the capital tied up at cost is €28,490.00, cash held in stock rather than a loss. Illustrative data.

## Put it into practice

- [Explore it: Inventory Insights](https://www.productmetrics.io/inventory-insights): Apply the definition to your products.
- [Read the guide: How to calculate stockout cost and revenue at risk](https://www.productmetrics.io/blog/stockout-cost-ecommerce): Work through the concept in more detail.

## For one product, and for an account

Safety stock and the stock that covers demand until the next delivery, sometimes called lead-time or cycle stock, are the part you meant to hold, so they come off before anything counts as excess. What is left is a question of quantity, not speed: a best seller can carry excess after one order that was too large.

Excess stock value at cost is the purchase cost of the units above your coverage threshold: cash tied up, not an expense or a loss. It comes back as the units sell, but meanwhile it cannot pay for the next order of a product that is running out. A markdown or write-off loss is a separate outcome, when stock sells below cost or not at all, and it grows more likely the longer the stock sits. Track the capital at cost, the money you paid for the stock, rather than what it would bring in at full price.

Inventory carrying cost, also called holding cost, is different: it is what keeping stock costs over time. As a yearly rate, it is annual inventory carrying costs ÷ average inventory value × 100. What goes in varies by business: the cost of the capital, storage space, insurance, handling, systems, shrinkage, damage and obsolescence. For example, €4,000.00 of such costs a year on €20,000.00 of average stock is a rate of 20%. At that rate, €10,000.00 of surplus held for six months costs about €1,000.00 to hold, and twice that over a full year.

Per product, the number tells you how long the surplus lasts: Winter Boot’s 340 excess units are 68 weeks of sales at 5 a week. Rolled up, it shows where the money sits; in the example, one brand holds €24,010.00 of the €28,490.00. Review the largest surplus at cost first and check its forecast, season, lifecycle and next confirmed delivery. If peak season is ahead, keep the buffer. If demand has fallen, buy less next time and promote or bundle it without giving the margin away. If it is no longer expected to sell, compare a markdown, a return to the supplier, a bulk sale and a write-off.

Inventory Insights in Product Metrics shows each product’s stock cover and its stock value at cost and at price. It flags slow movers with their excess cover in weeks and a reason: needs exposure, reduce spend, wait for season or free capital. Excess capital, the sum of excess stock value at cost, is shown per product and rolled up by category, brand and price range. Purchasing and clearance stay with you.

Ads can help clear excess stock, but only where they pay. Give exposure to excess products whose ads are profitable, and lower priority on products that are short of stock, so clicks do not run ahead of what you can ship. Stock cover reaches Merchant Center as a custom label you approve, so campaigns can treat the two groups differently.

## Common mistake

Valuing excess at selling price, or counting safety stock as excess. The first more than doubles the money at stake in the example; the second makes the buffer you chose look like a problem and pushes you towards the stockouts it was meant to prevent.

## Questions

### What is excess inventory?

Excess inventory, also called excess stock, surplus inventory or overstock, is the stock left once expected demand until your next delivery and your safety stock are covered. The product may still sell well; you just hold more of it than the coming weeks need.

### How do you calculate excess inventory?

For each product, multiply expected weekly demand by the weeks until the next delivery arrives, add safety stock, and subtract the result from units on hand. Count anything below zero as zero. Multiply the excess units by unit cost and add the products together to see the capital tied up.

### What is the difference between excess inventory, slow-moving inventory and dead stock?

Excess inventory measures quantity against need. Slow-moving inventory sells slowly compared with your other products, and dead stock has stopped selling altogether. Dead stock is almost all excess, because its expected demand is close to zero, while a slow mover bought in small amounts may have none.

### Should excess inventory be valued at cost or at selling price?

At cost: the same unit cost you use for cost of goods sold. That is the cash tied up in the stock. Selling price shows what the units would bring in at full price, which excess stock often does not reach once markdowns start.

### What should you do with excess inventory?

Start with the products that hold the most capital at cost. Keep the stock if demand is about to rise, such as a seasonal product before its peak. Otherwise buy less on the next order, give it exposure where its ads are profitable or bundle it with a product that sells. Stock that is no longer expected to sell goes back to the supplier, into a bulk sale or a markdown once holding it costs more than the discount, or gets written off.

### Does safety stock count as excess inventory?

No. Safety stock is a buffer you chose against demand or deliveries going off plan, so subtract it before you count excess. If the buffer is larger than a product’s variation calls for, change the safety stock setting rather than calling the buffer excess.

## Keep reading

- [Slow-moving inventory](https://www.productmetrics.io/glossary/slow-moving-inventory): Stock that sells slowly compared with your other products.
- [Days of inventory](https://www.productmetrics.io/glossary/days-of-inventory): Stock cover in days or weeks, the starting point for excess cover.
- [GMROI](https://www.productmetrics.io/glossary/gmroi): The gross profit each euro of stock at cost earns in a year.
- [Inventory turnover](https://www.productmetrics.io/glossary/inventory-turnover): How often stock at cost sells through in a year.
- [Safety stock](https://www.productmetrics.io/glossary/safety-stock): The buffer you subtract before anything counts as excess.
- [Safety stock calculator](https://www.productmetrics.io/safety-stock-calculator): Size the buffer per product before you judge what is excess.
- [Reorder point](https://www.productmetrics.io/glossary/reorder-point): Ordering at the right level keeps excess from building up.
- [Lead time](https://www.productmetrics.io/glossary/lead-time): Sets the weeks until the next delivery in the cover needed.
- [Stockout](https://www.productmetrics.io/glossary/stockout): The opposite risk: too little stock instead of too much.
- [Ecommerce inventory planning](https://www.productmetrics.io/blog/ecommerce-inventory-planning): Decide per product whether excess stock is held, promoted or cleared.
- [Dead stock inventory: how to find it and clear it](https://www.productmetrics.io/blog/dead-stock-inventory): When excess stops selling: how to find dead stock and clear it.

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Written by Berend Vrakking, founder of Product Metrics. Last updated 2026-10-25.

HTML version: https://www.productmetrics.io/glossary/excess-inventory