Why cost of sales matters to a first-time founder
Cost of sales links the direct cost of what was sold to the revenue reported for the same period. It is needed to calculate gross profit and assess pricing. If founders omit labour, materials, or delivery costs that belong here, a product can appear healthier than it really is.
Examples of cost of sales
A retailer begins with €20,000 of inventory, buys €50,000 more, and ends with €15,000. Its cost of sales is €20,000 + €50,000 − €15,000 = €55,000, before other directly attributable costs. If sales revenue is €90,000, gross profit is €35,000. Inventory rules determine which costs enter the calculation.
Common misunderstanding
Cost of sales is not the amount spent buying stock during the period. Unsold stock remains inventory rather than becoming an expense immediately. The term may overlap with cost of goods sold or cost of revenue, but usage differs by industry, accounting framework, and the company’s disclosed policy.
When to use it
Use it in monthly accounts, pricing reviews, stock planning, and gross-margin analysis. Match costs to the sales they generated and investigate changes in the percentage of revenue. Service firms should document which delivery labour belongs here. Statutory classification and inventory valuation must follow the applicable accounting rules.