Working capital tied up in inventory: what it costs and how to free it

By Elie Dufeu, CTO & Co-Founder, Metreecs. Published 31 August 2026.

Working capital tied up in inventory is the cash a retailer has already spent on stock that hasn't sold yet, money that's unavailable for payroll, marketing, or the next purchase order until the product moves. The cash conversion cycle (CCC = days inventory outstanding + days sales outstanding, minus days payable outstanding) is the standard way to measure how long that cash stays locked up.

For most retail finance teams, inventory is the single largest working capital line on the balance sheet, and the one with the most room to improve without cutting into service levels.

Key Takeaways

• Working capital tied up in inventory is cash spent on stock that hasn't converted to sales yet, measured through the cash conversion cycle (CCC = DIO + DSO - DPO).
• The Hackett Group's 2025 US Working Capital Survey found $1.7 trillion trapped in excess working capital across the top 1,000 US public nonfinancial companies, equal to 35% of gross working capital and 11% of aggregate revenue.
• Days inventory outstanding (DIO) worsened slightly in the 2025 survey, meaning cash is staying locked in stock longer, not less.
• Three structural causes drive excess working capital in inventory: safety stock set at the category level, replenishment cycles slower than the sell-through data, and buying decisions anchored to last year's numbers.
• AI-enabled forecasting and distribution operations can reduce inventory levels by 20 to 30% according to McKinsey, which translates directly into freed working capital.

What is working capital tied up in inventory?

Working capital tied up in inventory is the portion of a company's cash that has already been converted into unsold stock. Once a purchase order is paid, that cash isn't available again until the product sells, gets returned to a supplier, or gets written off. For a retailer running heavy inventory, this can represent a large share of total working capital, since stock sits in warehouses and stores for weeks or months before it converts back to cash.

This is different from inventory value on the balance sheet. Working capital tied up in inventory is a cash flow concept: it asks how long the cash stays locked up, not just how much the stock is worth. See how optimizing inventory at the product and location level targets that lock-up directly, instead of cutting stock evenly across the catalog.

The cash conversion cycle: the formula that measures the lock-up

The cash conversion cycle (CCC) is the standard formula for measuring how long cash stays tied up in the operating cycle: CCC = DIO + DSO - DPO.

• Days inventory outstanding (DIO) measures how long stock sits before it sells.
• Days sales outstanding (DSO) measures how long it takes to collect cash after a sale.
• Days payable outstanding (DPO) measures how long the company can hold onto cash before paying its own suppliers.

A retailer with a 90-day DIO, a 5-day DSO (most retail sales are immediate), and a 45-day DPO has a CCC of 50 days, meaning cash is locked up for 50 days between paying a supplier and having that cash available again. Lowering DIO is usually the fastest lever in that formula, since DSO is already close to zero for most consumer retail and DPO is constrained by supplier payment terms. See AI-driven inventory optimization for the levers that move DIO specifically.

How much capital is actually tied up in inventory right now

The scale of the problem is larger than most finance teams assume. The Hackett Group's 2025 US Working Capital Survey, based on the top 1,000 US public nonfinancial companies, found $1.7 trillion trapped in excess working capital, equal to 35% of gross working capital and 11% of aggregate revenue. The same survey found that days inventory outstanding worsened slightly rather than improving, meaning companies are holding cash in stock longer, not less, even as pressure on cash flow increases.

Naomi runs finance operations for a mid-market home décor retailer that carries roughly 1,800 active products across its own stores and a wholesale channel. When she pulled the CCC calculation for the first time in early 2026, DIO had crept from 78 days to 94 days over eighteen months without anyone flagging it as a problem, since gross margin looked stable and nobody was tracking cash lock-up as its own metric. The 16-day increase, multiplied across her cost of goods sold, was the equivalent of roughly six weeks of payroll sitting in a warehouse. Fixing it didn't require a new system first. It required someone to look at DIO as a cash metric instead of an inventory metric, and to ask the buying team which specific products had drifted, rather than approving next season's plan on the strength of the overall margin number alone.

How to calculate your own working capital tied up in inventory

The calculation takes four steps, using figures already on the balance sheet and income statement:

1. Pull average inventory value for the period, calculated as (beginning inventory + ending inventory) divided by two.
2. Pull cost of goods sold (COGS) for the same period.
3. Calculate DIO: (average inventory / COGS) multiplied by the number of days in the period.
4. Multiply DIO by average daily COGS to get the dollar or euro amount of cash currently tied up, not just the number of days.

A retailer with €2M in average inventory and €8M in annual COGS has a DIO of roughly 91 days. At an average daily COGS of about €22,000, that 91-day DIO represents the full €2M sitting in stock rather than in the bank. Tracking this figure every quarter turns working capital from an abstract finance term into a number a planning team can act on directly, the same discipline behind tracking DIO alongside the other KPIs that control networked inventory.

What drives excess working capital in inventory

Three structural patterns explain most of the buildup, and none of them are about anyone being careless with the buying budget.

Safety stock set at the category level. A category-wide safety stock rule (10 days of coverage for all home décor, for instance) overstates the buffer needed for stable, high-turnover products and understates it for genuinely volatile ones. The stable products end up sitting on cash that didn't need to be spent yet.

Replenishment cycles slower than the sell-through data. When replenishment runs weekly but sell-through data updates daily, purchase decisions lag reality by up to a week. That lag compounds every cycle, and the gap between when a product should have been reordered and when it actually was shows up as extra inventory sitting on the balance sheet.

Buying anchored to last year's numbers. A buying plan built from last year's actuals plus a flat growth assumption ignores shifts in channel mix, promotional calendar, or product lifecycle. Overbuying against a stale baseline is hard to spot because the excess looks like normal seasonal stock on a shelf report, not like an error on a spreadsheet.

How forecasting accuracy frees up working capital

Better forecasting attacks working capital at its source: fewer units bought that don't need to be bought yet. McKinsey research on AI-enabled distribution and forecasting finds inventory reductions of 20 to 30% are achievable without increasing stockout risk, which converts directly into freed cash rather than a one-time markdown event.

Product x location forecasting is what makes that reduction safe rather than reckless. A category-level forecast can only tell a buyer to trim inventory broadly, which risks cutting into the products that were actually turning fast. A forecast built at the product and store level identifies which specific products are overstocked and which are running lean, so the reduction in working capital comes from cutting the right units rather than an across-the-board haircut. Across Metreecs' work with home décor and F&B franchise planning teams, one mistake we repeatedly see is treating a working capital target as a flat percentage cut applied evenly across the catalog, which almost always ends up starving the fastest-moving products of the stock they need. Read more on how demand planning software builds that granularity into the forecast.

Elias oversees supply planning for a franchise network of quick-service restaurants sourcing perishable and shelf-stable ingredients across 60 locations. Working capital was tight enough in 2025 that the finance team asked every location to cut inventory by a flat 15%. The cut worked at some locations and caused ingredient shortages at others, because demand patterns varied by location and the flat percentage ignored that. Moving to product x location forecasting let Elias's team set a different target for each site based on actual turnover, which recovered most of the intended cash reduction without the stockouts that came with the blanket cut.

FAQ

What's the difference between working capital and working capital tied up in inventory? Working capital is current assets minus current liabilities, a broad measure of a company's short-term financial health. Working capital tied up in inventory is the specific portion of that figure locked in unsold stock, which is usually the largest and most controllable component for a retailer.

How do you calculate the cash conversion cycle? CCC = days inventory outstanding (DIO) + days sales outstanding (DSO) minus days payable outstanding (DPO). Each component is calculated from the balance sheet and income statement over a chosen period, typically a fiscal quarter or year.

Why does DIO matter more than DSO or DPO for most retailers? Most consumer retail sales settle in cash or near-instant electronic payment, so DSO is already close to zero and has little room to improve. DPO is largely set by supplier payment terms, which are hard to renegotiate quickly. DIO, driven by how much stock is bought and how fast it turns, is usually the lever with the most room to move.

Does reducing inventory always free up working capital? Only if the reduction targets the right products. Cutting inventory evenly across a catalog, without regard for which products are actually overstocked, risks creating stockouts on fast movers while barely touching the slow-moving stock that's actually tying up the cash.

How quickly can a retailer see working capital improvement from better forecasting? Improvements to DIO typically show up within one full replenishment cycle, often 4 to 8 weeks for fast-moving products, though the full effect on the cash conversion cycle usually takes a full quarter to show clearly in the financials. Slower-moving or highly seasonal categories take longer to register the change simply because the sell-through cycle itself is longer, not because the forecasting improvement was any less real.

Is a lower DIO always better for working capital? Not automatically. A DIO low enough to cause frequent stockouts trades one working capital problem for a revenue problem, since lost sales don't show up on the balance sheet the way excess inventory does. The right target is the lowest DIO a retailer can sustain without missing sales on its best-selling products.

Conclusion

Working capital tied up in inventory is cash sitting where it can't be used, and the cash conversion cycle is the formula that measures exactly how long it stays locked up. The Hackett Group's finding that $1.7 trillion remains trapped in excess working capital, with DIO trending the wrong direction, shows this isn't a problem that fixes itself as pressure on cash flow increases. The fastest, safest path to freeing that cash is forecasting accurate enough to cut the right inventory instead of an even amount everywhere. Book a demo to see how product-level forecasting identifies exactly where your working capital is sitting idle.

Sources

• The Hackett Group, "2025 Working Capital Survey: Payables Rebound, but Receivables and Inventory Lag". Source for the $1.7 trillion excess working capital figure, the 35% of gross working capital and 11% of aggregate revenue statistics, and the DIO trend among top 1,000 US public nonfinancial companies.