Cost of Goods Sold (COGS) is the direct cost of producing or buying the products you sold in a period. You calculate it as Beginning Inventory + Purchases − Ending Inventory. COGS drives gross profit, gross margin, and your tax bill, so accurate tracking is essential. This guide covers formulas, examples, inventory methods, and ways to reduce COGS, with help from Cashbook Acc.
Every product-based business, from a Shopify store to a manufacturer, lives or dies by one number: what it costs to put a sellable product in a customer's hands. That number is Cost of Goods Sold, or COGS. If you misstate it, your profit, pricing, and taxes are all wrong.
COGS appears at the top of your income statement, right below revenue. Subtract it from sales and you get gross profit, the money left to pay rent, marketing, salaries, and your own paycheck. A small error in COGS can swing net income by thousands of dollars.
In this guide you will learn what COGS includes, how to calculate it step by step, how inventory valuation methods change the result, and how to use COGS to improve margins. If you want a professional to handle it, our ecommerce bookkeeping services keep your COGS accurate every month.
Talk to a bookkeeping expert who understands inventory and profitability.
📞 Call Us 📅 Book Meeting ✉️ cashbookconsultancy@gmail.comCOGS is the total direct cost of the goods a business sold during a specific period. For a retailer, that means the price paid to suppliers plus freight-in. For a manufacturer, it adds direct labor and factory overhead tied to production. Costs for goods still sitting in your warehouse are not COGS; they remain an asset called inventory until sold.
Service businesses usually do not report COGS, though some use a similar line called "cost of revenue" or "cost of services."
| Included in COGS ✅ | Excluded from COGS ❌ |
|---|---|
| Raw materials and purchased inventory | Marketing and advertising |
| Direct labor for production | Sales team salaries and commissions |
| Freight-in and import duties | Outbound shipping to customers (often an operating expense) |
| Factory overhead (utilities, rent of production space) | Office rent and administrative costs |
| Packaging that ships with the product | Software subscriptions and professional fees |
| Inventory write-downs and spoilage | Interest and income taxes |
| Line Item | Amount |
|---|---|
| Net Sales Revenue | $200,000 |
| Beginning Inventory | $40,000 |
| + Purchases (incl. freight-in) | $110,000 |
| − Ending Inventory | $30,000 |
| = COGS | $120,000 |
| Gross Profit ($200,000 − $120,000) | $80,000 |
| Gross Margin ($80,000 ÷ $200,000) | 40% |
Related ratio: Inventory Turnover = COGS ÷ Average Inventory. In our example, average inventory is $35,000, so turnover is about 3.4 times per year, meaning stock sells through roughly every 106 days.
When purchase prices change, the method you use to assign costs to sold items changes COGS. Here is how the three common methods compare during rising prices.
| Method | How It Works | COGS in Rising Prices | Net Profit |
|---|---|---|---|
| FIFO | Oldest costs are expensed first | Lower | Higher |
| LIFO (US only) | Newest costs are expensed first | Higher | Lower (less tax) |
| Weighted Average | Uses average cost per unit | Moderate | Moderate |
Note that LIFO is permitted under US GAAP and IRS rules but not under IFRS. Once you choose a method for tax purposes, changing it requires IRS approval (Form 3115), so decide with a professional's guidance.
COGS is usually the largest expense a product business has, so even small shifts move your bottom line. Consider the same $200,000 in sales under different COGS levels:
Pricing example: If a product costs $24 and you want a 40% gross margin, the minimum price is $24 ÷ 0.60 = $40.
Online sellers face extra complexity: multiple channels, returns, bundles, marketplace fees, and landed costs. Include product cost, inbound freight, duties, and packaging in COGS. Marketplace fees and ads are typically operating expenses. Returns should reduce both revenue and COGS when items go back into sellable stock.
Many stores skip proper inventory accounting and use bank deposits to guess profit. That hides losses. Our ecommerce bookkeeping team syncs Shopify, Amazon, and Stripe data so COGS is correct. If your books are already behind, our clean-up services repair historical records first.
| Mistake | Consequence | Fix |
|---|---|---|
| Ignoring freight-in and duties | Overstated profit | Track landed cost per item |
| No physical inventory count | Wrong ending inventory | Count at least annually; cycle count monthly |
| Mixing operating expenses into COGS | Distorted margins | Write a clear classification policy |
| Switching valuation methods casually | Inconsistent reports, IRS issues | Stay consistent; file Form 3115 if changing |
| Not writing off obsolete stock | Inflated assets | Review slow movers quarterly |
COGS reduces your gross income, so it directly lowers taxable profit. Sole proprietors report it on Schedule C (Part III), while corporations report it on Form 1125-A. Weak records mean the IRS can disallow deductions. Plan ahead for payments with our guide on quarterly estimated tax payments, and let our tax preparation team file correctly. Selling taxable goods? See our sales tax services, and if you employ production staff, our payroll services ensure direct labor is recorded properly. New Jersey businesses can also explore tax services in New Jersey.
Let Cashbook Acc calculate COGS, clean your books, and build a clear picture of your margins.
📞 Call Us 📅 Book Meeting ✉️ Email UsCOGS = Beginning Inventory + Purchases − Ending Inventory. Include freight-in and direct production costs in purchases.
Inventory is an asset until sold. Once sold, its cost becomes COGS, an expense on the income statement.
It varies by industry. Retail often runs 50–70% of revenue, while software and services sit far lower. Compare against industry peers and your own trend.
Inbound shipping (freight-in) is part of COGS. Outbound shipping to customers is commonly an operating expense, though policies vary.
Most do not report COGS, but they may track a "cost of revenue" for direct delivery costs such as contractor labor.
COGS is more than a line on a financial statement. It tells you whether your products make money, how to price them, and how much tax you owe. Calculate it consistently, choose the right valuation method, and review it monthly. If you want expert support, Cashbook Acc is ready to help.
Turn accurate COGS into higher profits.
📞 Call Us 📅 Book Meeting ✉️ cashbookconsultancy@gmail.com