Cost per lead formula
CPL is what you spent on a campaign divided by the leads it produced in the same period. A lead is whatever you count as one: a lead form submitted inside an ad (Google Ads lets people send their contact details from Search and Performance Max ads without visiting your site),[1] a website form, a call or a demo request. In Google Ads and Microsoft Advertising, a lead you track as a conversion is reported as cost per conversion: cost ÷ conversions.[2][4] CPL is that figure when the conversion is a lead.
- Cost per lead$40.00
- Leads per $1,00025
- Customers from 125 leads at 10%12.5
- Cost per customer$400
The CPL calculator also turns leads into customers. A cheap lead that never buys is expensive, so the number that matters for the business is cost per customer, the same quantity the CAC calculator measures across all channels.
How much can you pay per lead?
A lead is worth the gross profit of a customer times the chance that the lead becomes one. At $1,200 of revenue, a 60% gross margin and a 10% close rate, a lead is worth $72.00; any CPL above that loses money before overhead. If you bid with Target CPA on lead conversions, this break-even CPL is the ceiling for the target.[3]
| Close rate | $300 | $1,200 | $5,000 |
|---|---|---|---|
| 2% | $3.60 | $14.40 | $60.00 |
| 5% | $9.00 | $36.00 | $150 |
| 10% | $18.00 | $72.00 | $300 |
| 20% | $36.00 | $144 | $600 |
Each column scales in a straight line with the close rate: doubling how many leads you close doubles what you can pay for them. That is why lead quality work (better qualifying questions, faster follow-up) often lowers the true cost of growth more than cutting CPL. Track the funnel stage by stage with the sales conversion rate page.
CPL vs CPA vs CAC
CPL is a CPA where the action is a lead. The CPA calculator handles any conversion, including purchases; CAC adds sales salaries and every other acquisition cost and divides by paying customers only. Report all three with their definitions, because the same campaign can show a $40 CPL, a $40 CPA and a $400 CAC.
Cost per lead mistakes
- Counting duplicates and spam. Repeat submissions and junk forms inflate leads and make CPL look cheap. Count unique, valid leads.
- Comparing different lead types. A newsletter sign-up and a demo request are not the same lead; compare CPL only within one lead type.
- Stopping at CPL. Without a close rate, a falling CPL can hide rising cost per customer. Add the close rate in the calculator.
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Frequently asked questions
How do you calculate cost per lead?
Ad spend ÷ number of leads in the same period. $5,000 ÷ 125 leads = $40.00 per lead.
What is a CPL calculator?
A tool that divides spend by leads and, given a close rate and deal value, turns CPL into cost per customer and the highest CPL that breaks even.
What is the maximum cost per lead I can afford?
Revenue per customer × gross margin × lead-to-customer rate. $1,200 × 60% × 10% = $72.00.
Is CPL the same as CPA?
CPL is a CPA where the conversion is a lead. CPA can be any action, including a purchase.