The quick answer
Gross profit is sales minus cost of goods sold. Gross margin expresses that profit as a percentage of sales. It helps compare products and periods, but it does not include every cost of running the shop.
Use consistent amounts and a supported cost basis. For a registered business, tax treatment can affect which amounts belong in revenue and cost. Ask your accountant to confirm the basis before comparing reports.
Before you begin
- Sales after relevant returns and discounts.
- Supported cost of the goods actually sold.
- A consistent treatment of tax and the reporting period.
See how the pieces connect
Revenue
Find the supported net sales amount.
Cost
Match the cost of goods sold.
Subtract
Calculate gross profit.
Divide
Express profit as a percentage of sales.
Work through the steps
Define net sales
Use the relevant sales amount after accepted discounts and returns. Do not use collections for old bills as new sales. Confirm whether recoverable or payable tax is excluded on the chosen accounting basis.
Identify cost of goods sold
Use the supported cost for the quantity sold, following the accountant’s valuation method. The latest supplier price alone may not represent the cost of older stock sold during the period.
Calculate gross profit
Subtract cost of goods sold from net sales. Keep the period and units consistent. A negative result needs investigation into pricing, returns, purchase cost and data quality.
Calculate margin
Divide gross profit by net sales and multiply by 100. If net sales are zero, the percentage is not defined. Do not divide by cost: that produces markup instead of margin.
Compare like with like
Review products, departments or periods with consistent tax and cost treatment. Discounts, wastage and changes in purchase price can affect results. Do not compare a seasonal clearance with a normal trading month without context.
Review the full business result
Subtract relevant operating expenses separately to assess the wider result. Gross profit must help cover rent, salaries and other costs. A strong gross margin alone does not guarantee positive net profit or cash flow.
A worked example
Margin uses sales as its denominator
Simplified values on one consistent tax basis.
| Calculation | Result |
|---|---|
| Net sales | ₹10,000 |
| Cost of goods sold | ₹7,000 |
| Gross profit | ₹3,000 |
| Gross margin: ₹3,000 ÷ ₹10,000 × 100 | 30% |
| Markup: ₹3,000 ÷ ₹7,000 × 100 | 42.86% |
The same ₹3,000 difference produces 30% margin and about 42.86% markup. Label the percentage correctly.
Common mistakes to avoid
- Confusing markup with margin.
- Using all purchases instead of cost of goods sold.
- Mixing tax-inclusive and tax-exclusive amounts.
- Calling gross profit the owner’s final take-home amount.
Questions you might have
What happens when sales are zero?
Gross margin cannot be calculated by dividing by zero. Review the underlying amounts instead.
Does Dukanam replace the accountant’s valuation decision?
No. Use supported records and confirm the appropriate cost and tax basis with your accountant.
Dukanam
A smart, low-cost choice for small-business GST billing
Dukanam brings billing, purchases, stock, customer balances, payments and reports together. It is built for Indian small businesses that want clear records without a complicated setup.
Best suited to shops that want connected everyday billing and bookkeeping, web and mobile access, and nine product languages. Choose the plan that includes the features you need.
GST-aware billing and preparation depend on your plan. Review records before filing on the GST portal; Dukanam does not directly submit GST returns, government e-invoices or e-way bills.
Current plans with GST preparation
- Advanced Plan₹299.00 per month
Check annual prices, limits, applicable taxes and checkout terms. Paid plans do not include a free trial.
Sources and further reading
Official rules and portal screens can change. Use the linked authority for the current requirements; the figures in our worked examples are illustrative.