Procurement Cost Calculator

The total cost of a purchased item consists of at least five blocks: material cost (quantity × unit price), process cost of order handling (request for quotation, purchase order, goods receipt, invoice verification), cost of the supplier relationship (qualification, audit, master data maintenance, supplier evaluation), inventory holding cost (space, handling, insurance, shrinkage) and cost of capital (working capital tied up, less the trade credit granted by the payment terms). On top of that come shortage and downtime cost whenever an item is unavailable. The unit price is the only one of these blocks that appears on the invoice — which is why it is overrated. For C-parts and small quantities, process cost often reaches or exceeds the material value — the documented process costs per purchase order in the sources section of this page (BME 2025; Mercateo/HTWK 2017) show the order of magnitude.

The cost of capital is formed from two opposing effects. First: the capital tied up in the average inventory, valued at your cost of capital. With uniform consumption, the average inventory equals half the lot size — valued in euros: (annual demand ÷ (2 × number of purchase orders)) × unit price. Second: the supplier credit resulting from the payment terms. As long as you have not paid, the supplier finances the goods — this relieves your capital commitment by annual goods value × payment terms ÷ 365 × interest rate. The calculator reports both figures separately and nets them. A negative balance is possible and correct: with long payment terms and low inventory, the supplier finances more than you tie up.

Many rules of thumb lump both into a single inventory holding rate. That is unusable for a scenario comparison, because the two figures behave differently: physical inventory cost (space, racking, handling, insurance, shrinkage, stocktaking) is incurred as long as the goods sit with you. Cost of capital additionally depends on the payment terms. If inventory holding moves to the supplier under a blanket order agreement, the physical share disappears completely, while the cost of capital changes only through the altered call-off structure. In this calculator, please therefore enter an inventory carrying rate WITHOUT any interest component.

A blanket order agreement is not a free saving but a trade of flexibility for commercial terms. The main disadvantages: minimum purchase commitment — the agreed quantity has to be taken, even if demand falls. Contract term — early exit is usually only possible by mutual consent and normally against compensation. Demand-change risk — in the event of a design change, end of series or a drop in demand, the residual quantity remains on your books. Price lock-in works in both directions — you cannot benefit from falling market prices during the term. And finally concentration risk: the more volume rests on a single source, the harder a failure hits. These points cannot be monetized within the calculation and must be placed qualitatively alongside the result.

The calculator also shows negative results — and that is the normal case in several constellations. If the process cost per purchase order and the cost per supplier relationship are low in your company, there is too little to harvest. If the previous suppliers are specialists with significantly better individual prices, the bundled price can eat up the advantage. If bundling leads to larger lots and therefore higher inventory, inventory and capital cost rise against the saving. And if you have to keep a second source for risk reasons anyway, the saving on supplier cost largely disappears. Always check the breakdown by cost block, not just the total.

Four values should ideally come from within your company: the process cost per purchase order (from an activity-based costing exercise covering purchasing, goods receipt and accounts payable), the annual cost per supplier relationship (qualification, audits, master data, supplier evaluation, complaint handling), your inventory carrying rate and your internal cost of capital (usually your company weighted average cost of capital). This calculator deliberately pre-fills nothing, because the spread of these values between companies is large. Where published study figures exist, you can apply them as flagged reference values with one click — for a robust procurement business case, replace them with your own controlling figures; the flag in the summary shows where that is still outstanding.

Every reference value comes from a published, named source with a year — such as the BME purchasing key figures 2025, the Mercateo/HTWK Leipzig study on process costs, the KPMG Cost of Capital Study 2025 or the Creditreform payment indicator — and is classified by source type (association/study, specialist publisher, consulting practice). The default application is the conservative end of the range — the end that makes consolidation look worse — wherever that direction can be determined unambiguously; for the cost of capital the direction depends on the ordering structure, so both values are offered neutrally; applied values are flagged in the copyable summary as literature values with their source. Fields for which no robust independent source exists — the annual cost per supplier relationship, shortage and downtime cost, and all blanket-order terms — deliberately remain without a reference value: better an empty field than a number that will not survive scrutiny in a sourcing discussion. Literature as of July 2026.