Cost of Goods Sold Calculator

How to Use the Calculator

1. Enter the Beginning inventory — the value of goods on hand at the start of the accounting period, taken from your opening balance or prior period's ending inventory.
2. Enter the Purchases — the total cost of inventory purchased (or, for manufacturers, produced) during the period, at cost rather than retail price.
3. Enter the Ending inventory — the value of goods remaining in stock at the end of the period, usually from a physical count or perpetual inventory system.
4. Read the Cost of Goods Sold result, expressed in dollars, below the inputs.

What Is Cost of Goods Sold?

Cost of Goods Sold (COGS) is the direct cost of the goods a business sells during an accounting period. For a retailer, it is the amount paid to suppliers for the merchandise sold. For a manufacturer, it includes raw materials, direct labor, and factory overhead tied to the finished goods sold. COGS appears on the income statement immediately below revenue and is subtracted from it to arrive at gross profit.

What COGS deliberately excludes is just as important as what it includes. Operating expenses such as rent, marketing, distribution, administrative salaries, and interest are not part of COGS — they are reported further down the income statement. Keeping these categories separate is what makes the gross profit margin meaningful as a measure of production or buying efficiency.

COGS matters for several practical reasons. It determines gross profit, which drives pricing and margin decisions. It affects taxable income, since a higher COGS means a lower reported profit and lower income tax. It also serves as a check on inventory management: if the calculated COGS does not match what your sales data suggests, it may indicate shrinkage, theft, miscounted stock, or accounting errors. Tools like the days in inventory and inventory stock calculators can extend this analysis.

Inventory Valuation Methods

The simple COGS formula works identically under any inventory costing method, but the numbers you plug into it depend on which method your business uses:

• FIFO (First In, First Out): the oldest goods are sold first. In periods of rising prices this produces a lower COGS and higher profit. See the FIFO inventory cost calculator.
• LIFO (Last In, First Out): the newest goods are sold first, producing a higher COGS when prices rise. Not permitted under IFRS, but allowed in the US under GAAP.
• Weighted Average Cost: each unit is valued at the average cost of all units in stock, smoothing out price fluctuations.

Assumptions and Limitations

• The calculator assumes all inventory changes come from purchases and sales. It does not separately track write-offs, shrinkage, returns to suppliers, or goods damaged in storage — these should be reflected in your ending inventory count or adjusted before entering it.
• Enter all three values at cost, not retail price. Mixing a cost-based beginning inventory with a retail-value purchase total will distort the result.
• The formula gives period totals, not unit-level detail. For product-by-product margins you need a per-SKU breakdown from your accounting or inventory system.
• COGS is not the same as total expenses. Do not add shipping to customers, sales commissions, or marketing costs — these belong in operating expenses.
• Consistency matters for tax purposes: once you choose an inventory valuation method, keep using it across periods unless you formally change it.

Practical Tips

• Take a physical inventory count at the end of each period; an accurate ending inventory value is the single biggest source of COGS accuracy.
• Remember that ending inventory of one period is the beginning inventory of the next — carry it forward unchanged.
• Compare COGS to revenue as a percentage over time. A rising COGS ratio with flat prices suggests supplier costs are eating into your margins, which may call for repricing or renegotiation.
• If you plan production or purchasing volumes, pair COGS with the economic order quantity and ending inventory calculators to plan stock levels.