What is profit margin?
Profit margin is the percentage of revenue you keep as profit after costs. It's one of the most important measures of business health — two companies with identical revenue can have wildly different margins, and the higher-margin one is almost always the stronger business.
Profit margin % = (Revenue − Cost) ÷ Revenue × 100
Sell something for $100 that cost $60, and your margin is (100 − 60) ÷ 100 = 40%. You keep 40 cents of every dollar of revenue.
How to calculate profit margin (step by step)
- Pick your revenue and cost numbers — same time period, same scope (per unit or whole business).
- Subtract cost from revenue — that's your profit in dollars.
- Divide profit by revenue × 100 — that's your margin percentage.
The same formula works at any scale: a single SKU, a product line, or the entire P&L. Just match the revenue and cost to the same scope.
Worked example: three layers of margin on the same P&L
Take a small ecommerce business with the following monthly numbers:
| P&L line | Amount | Calculation |
|---|---|---|
| Revenue | $120,000 | Top line |
| − COGS (product + shipping) | $48,000 | Direct product cost |
| = Gross profit | $72,000 | Revenue minus COGS |
| Gross margin | 60% | $72,000 ÷ $120,000 |
| − Operating expenses (ads, payroll, rent, tools) | $54,000 | |
| = Operating profit | $18,000 | Gross profit minus OpEx |
| Operating margin | 15% | $18,000 ÷ $120,000 |
| − Interest, taxes, depreciation | $6,000 | |
| = Net profit | $12,000 | Bottom line |
| Net margin | 10% | $12,000 ÷ $120,000 |
Each layer of cost peels away margin. A healthy 60% gross margin can still turn into a thin 10% net margin once operating costs and taxes are subtracted. That's why operators track all three — gross tells you if the product works, operating tells you if the business model works, and net tells you if the whole enterprise works.
Gross, operating, and net margin
"Profit margin" can mean several things depending on which costs you subtract:
- Gross margin — revenue minus cost of goods sold (what this calculator computes by default). Answers: "Does each sale cover its own direct cost?"
- Operating margin — also subtracts operating expenses like ads, salaries, and rent. Answers: "Does the core business generate profit?"
- Net margin — subtracts everything, including taxes and interest. Answers: "What's left for owners after all bills?"
Enter different cost figures to compute whichever margin you need. For per-unit analysis, use the selling price as revenue and unit cost as cost.
Margin vs markup
Margin is profit over revenue; markup is the same profit over cost. A 40% margin equals a ~67% markup. Keep them straight when pricing — and remember that your margin directly sets your break-even ROAS: the thinner the margin, the higher the return you need from every ad dollar. At a 25% margin you need 4x ROAS to cover product cost alone; at 60% you only need ~1.67x.
How to improve profit margin
Margin improvement compounds: a few points of margin gain drops straight to the bottom line.
- Raise prices — the most direct lever, especially if your product has strong differentiation.
- Lower COGS — negotiate with suppliers, change materials, or increase order quantities.
- Improve product mix — shift sales toward higher-margin SKUs.
- Cut operating waste — audit ad spend with ROAS, optimize conversion with CVR.
For choosing between margin-based ROI and revenue-based ROAS when reporting results, see ROAS vs Marketing ROI.
Use margin with marketing metrics
Gross margin is the hidden variable in every marketing equation. Your marketing ROI depends on it. Your break-even CAC depends on it. And your profit per order feeds directly into AOV and LTV calculations. Always use the same margin figure across tools so your numbers tie out.