What does this purchase order really cost?
Storage, shrinkage and the cash it ties up, from the supplier deposit to the last payout, with the date the next order has to go out. Then the 2026 turnover benchmarks for your category, converted to the same cost basis as your own numbers.
Everything runs in this browser. Nothing you enter or import is sent to Volumetris unless you copy a share link.
The true cost of one purchase order.
The numbers in it are an example: a 5,000-unit order. Change any of them, fill them from your own sales export, or compare two scenarios side by side.
Fill the calculator from your own sales. An orders export from Amazon, Shopify, Walmart or TikTok Shop, as CSV, TSV or XLSX. Sixty to ninety days of orders works best. The file is read on this page, in your browser, and never uploaded.
Which export: Amazon, Reports, then the All Orders report or the Detail Page Sales and Traffic business report. Shopify, Orders, then Export. Walmart and TikTok Shop, the orders export.
Supplier terms and timing
Cash position for this order
Season shapes are illustrative: they move sales and payouts inside the same sell-through window. Event dates come from public calendars; Prime Day and Prime Big Deal Days are expected windows, and Chinese New Year closures are approximate.
Week by week
Estimates only, from the numbers you enter. Platform presets are starting points from published pricing and may differ from your account. A share link carries your inputs in the link itself, so only send it where you are happy for them to go.
The order-by date is the number that matters. We work it out for every SKU, every week, with the cash each order needs, and walk it with you on a 30-minute call before it is late.
Book a fit callInventory turnover benchmarks by industry, 2026.
Two public sources, read on the basis you actually use.
Inventory turnover is cost of goods sold divided by average inventory, both at cost. Days on hand is 365 divided by turns. Public datasets usually report inventory against sales instead, and that makes every industry look faster than it is on its own books. The table below converts each industry to the cost basis using that industry’s own gross margin, from the same dataset, so the turn you compare with is measured the way yours is.
| Industry, US public companies | Firms | Inventory / sales | Gross margin | Turns, cost basis | Days on hand | Turns, sales basis |
|---|---|---|---|---|---|---|
| Retail (grocery and food) | 15 | 5.49% | 26.31% | 13.4 | 27 | 18.2 |
| Retail (general merchandise) | 23 | 8.67% | 33.18% | 7.7 | 47 | 11.5 |
| Auto parts | 35 | 12.47% | 15.84% | 6.7 | 54 | 8.0 |
| Food processing | 78 | 13.41% | 23.23% | 5.7 | 64 | 7.5 |
| Beverage (soft) | 27 | 8.06% | 54.74% | 5.6 | 65 | 12.4 |
| Electronics (consumer and office) | 8 | 13.63% | 38.77% | 4.5 | 81 | 7.3 |
| Recreation (toys, sporting and leisure goods) | 49 | 13.71% | 39.79% | 4.4 | 83 | 7.3 |
| Household products | 110 | 11.55% | 51.04% | 4.2 | 86 | 8.7 |
| Retail (distributors) | 62 | 16.67% | 30.57% | 4.2 | 88 | 6.0 |
| Furniture and home furnishings | 27 | 18.29% | 30.28% | 3.8 | 96 | 5.5 |
| Shoes | 11 | 16.43% | 43.88% | 3.4 | 107 | 6.1 |
| Retail (special lines) | 94 | 18.76% | 35.30% | 3.4 | 106 | 5.3 |
| Beverage (alcoholic) | 14 | 19.75% | 46.96% | 2.7 | 136 | 5.1 |
| Healthcare products | 204 | 17.59% | 54.00% | 2.6 | 140 | 5.7 |
| Apparel | 35 | 19.25% | 56.88% | 2.2 | 163 | 5.2 |
| All industries, excluding financials | 4,822 | 8.99% | 34.39% | 7.3 | 50 | 11.1 |
Source: Aswath Damodaran, NYU Stern, working capital ratios and margins by industry (US), data as of January 2026. Cost-basis turns are (1 − gross margin) ÷ (inventory ÷ sales). Apparel turns 5.2 times a year against sales and 2.2 against cost: the cost figure is the one to set beside your own.
The Census Bureau gives a second, store-level view: how many months of inventory retailers hold against one month of sales at the current pace.
| Retail stores, US | Months of stock, Aug 2026 | A year earlier | Turns, sales basis |
|---|---|---|---|
| Food and beverage stores | 0.82 | 0.80 | 14.6 |
| Retail excluding motor vehicles and parts | 1.19 | 1.22 | 10.1 |
| Retail trade, total | 1.36 | 1.37 | 8.8 |
| General merchandise stores | 1.39 | 1.37 | 8.6 |
| Furniture, home furnishings, electronics and appliance stores | 1.80 | 1.78 | 6.7 |
| Clothing and clothing accessories stores | 2.02 | 2.05 | 5.9 |
| Building materials and garden supplies | 2.53 | 2.49 | 4.7 |
| Department stores | 2.60 | 2.57 | 4.6 |
Source: U.S. Census Bureau, Manufacturing and Trade Inventories and Sales, August 2026, release CB26-166, October 15, 2026. Seasonally adjusted; the August 2026 figures are preliminary. Turns are 12 divided by the ratio, on a sales basis.
Fastest
Food and general merchandise: under a month and a half of stock against sales, and around eight turns or more even on a cost basis.
Slowest
Apparel, healthcare products and alcoholic beverages: about four months or more of stock on hand on a cost basis.
The number to beat
Your own. The turn your lead time and sell-through support, with the order-by date that keeps it true, is the one the calculator above works out.
What is a good inventory turnover ratio for ecommerce?
The one your lead time allows without a stockout. A brand that waits two months for stock and keeps two weeks of safety stock cannot turn like a grocer, and should not try. Compare yourself with your category on a cost basis, in the first table, then set the calculator to your real lead time and sell-through to see the turn your cycle supports.
How do I calculate inventory turnover and days on hand?
Turnover is cost of goods sold for the year divided by average inventory at cost; average inventory is the start plus the end of the period, divided by two. Days on hand is 365 divided by turnover: five turns is 73 days, eight is about 46.
Why do public benchmarks look faster than my numbers?
Mostly the basis. Public datasets measure inventory against sales, which inflates the turn by the margin: apparel is 5.2 turns against sales and 2.2 against cost. Compare your cost-basis turn with the cost-basis column, and the gap usually shrinks or flips.
Why is the cost of capital lower here than in other calculators?
Because it is charged only on the cash that is actually out each day. Many estimators charge the whole order for the whole cycle, as if you paid in full on day one and nothing came back until the last sale. Your deposit terms, and the payouts that arrive as stock sells, both shorten the time the money is really gone, and this calculator counts them. The line under the cost breakdown shows what the shortcut would have said.
What happens to the files I import?
Nothing leaves your browser. The file is read by this page on your machine, the order lines are added up per SKU, and only the average price and sales speed of the SKU you pick are written into the calculator.
Want this for every SKU, every week?
The order-by date, the cash it needs and the call before it is late, for every product you sell. That is the weekly plan.