Marketing ROI Explained: Cost Per Lead, CAC and ROAS for Small Businesses
Three numbers tell you whether your marketing pays: what a lead costs, what a customer costs and how much comes back. Here is what each means, how to calculate them and what to do next.
Short answer: cost per lead tells you what an enquiry costs, customer acquisition cost tells you what a paying customer costs, and ROAS tells you how much revenue each rupee of spend brings back. Together they show whether to spend more, fix something or stop.
| Metric | Formula | Question it answers |
|---|---|---|
| Cost per lead (CPL) | Spend ÷ leads | What does an enquiry cost? |
| Customer acquisition cost (CAC) | Spend ÷ new customers | What does a customer cost? |
| ROAS | Revenue ÷ spend | How much comes back per rupee? |
| Profit | Revenue × margin − spend | Did it pay after delivery costs? |
A worked example
Suppose you spend ₹50,000, get 80 leads, and 10 percent become customers with an average sale of ₹15,000 and a 40 percent margin. That is 8 customers, ₹1,20,000 revenue, a CPL of ₹625, a CAC of ₹6,250 and a ROAS of 2.4. Profit is ₹1,20,000 × 0.4 − ₹50,000 = −₹2,000, so the spend does not quite pay back yet.
What do you fix first?
- 1.The close rate: faster replies and a follow-up often lift it more than any ad change.
- 2.The cost per lead: better targeting, a sharper offer and a clearer landing page.
- 3.The sale value: bundles, add-ons and repeat purchase offers.
Enter your own numbers and see CPL, CAC, ROAS and profit, plus what a better close rate would do.
Open the marketing ROI calculatorTag your links so you can see which channel produced each customer.
Read the UTM tracking guideWe plan, run and measure digital marketing for businesses in India and abroad.
Start a conversationFrequently asked questions
What is a good ROAS?
It depends on your margin. If you keep 40 percent of each sale after delivery costs, you need a ROAS above 2.5 just to break even on spend. Use your own margin to find your break-even ROAS.
What is the difference between CPL and CAC?
Cost per lead is spend divided by leads. Customer acquisition cost is spend divided by customers. CAC is higher because not every lead buys.
How do I lower my cost per customer?
Improve the close rate by replying faster and following up, lower the cost per lead with better targeting and a clearer landing page, and raise the sale value with packages and upsells.
Should I include my own time in marketing spend?
For decisions, yes where you can. At minimum include ads, tools and agency fees, and note the time separately.
How often should I review these numbers?
Monthly for most small businesses, weekly while you run paid campaigns.
Tejas Patel
Founder & CEO, VeltrexLabs
Tejas is the Founder & CEO of VeltrexLabs, a product-focused development agency that has shipped MVPs for 13+ startups across food-tech, SaaS, e-commerce, and enterprise software.
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