Free tool · Google Ads and Meta Ads
CPA and Cost Per Lead Calculator with real customer cost
Results
Cost per lead
$37.50
$1,500 ÷ 40 leads
Customers from these leads
10.0
leads × close rate
Cost per customer (CAC)
$150.00
ad spend ÷ customers
Leads needed per customer
4.0
1 ÷ close rate
A $38 lead that closes 25% of the time is really a $150 customer. Compare lead sources on that number, not the lead price.
How it works
The formulas
Cost per lead / sale / purchase
Ad spend ÷ results. One formula, three names. What changes is what you count as the result.
Customers from leads
Leads × lead-to-customer rate. 40 leads at a 25% close rate is 10 customers.
Customer acquisition cost
(Ad spend + other costs) ÷ customers. Add agency fees, tools or creative if you want the full figure rather than the ads-only one.
Why I never judge a campaign by cost per lead alone
Cheap leads are the easiest thing in the world to buy. Broaden the targeting, use an Instant Form with no questions, and the cost per lead in Meta drops nicely. Then sales says none of them pick up the phone.
So when I compare two campaigns or two platforms, I look at cost per customer. A Google search campaign at $70 a lead that closes 30% of the time costs about $233 per customer. A Facebook campaign at $25 a lead that closes 5% costs $500. The "expensive" one is half the price where it counts. (Those are illustrative numbers, but the pattern is one I see often.)
That's why the calculator asks for a close rate in Leads mode. Not sure of your close rate? The marketing funnel calculator works it out from your lead and customer counts. If you don't track it yet, a rough count from last month's leads in your CRM, or even a spreadsheet, is far better than nothing.
A worked example
These are example numbers, the calculator's defaults. A home services company spends $1,500 on ads in a month and gets 40 leads: cost per lead is 1,500 ÷ 40 = $37.50.
They turn about 1 in 4 into a paying job, so 40 × 25% = 10 customers. Cost per customer: 1,500 ÷ 10 = $150. Add a $300 management fee in "other costs" and the full CAC is 1,800 ÷ 10 = $180.
If an average first job is worth $600, the CAC is 30% of it, which leaves room. If the job were $200, the same campaign would be losing money on the first sale, even though $37.50 a lead sounds cheap.
Choosing the right mode
Leads
For service businesses: law firms, clinics, contractors, B2B. Count real enquiries, including calls and chats, not test submissions.
Sales
When the sale is tracked separately from the lead, such as a booked and paid appointment, or a deal marked won in your CRM.
Purchases
For online stores, where the purchase happens on the site. To see how high this can go before you lose money, use the break-even ROAS calculator.
Things that quietly distort CPA
- Counting the same lead twice when it fills the form and then calls.
- Test leads and spam left in the count. I always remove these before reporting.
- Comparing a platform's CPA with a different conversion window to another platform's.
- Mixing brand and non-brand search in one figure. Brand searches are cheap and would have come anyway.
- Using last month's spend with this month's sales. Long sales cycles need the leads and the closes matched up.
What to do with the number
Once you know your CAC and what a customer is worth, you know your ceiling. The max CPC calculator turns that into the most you can bid per click on Google, and the budget calculator shows how many leads a given budget should produce. If the cost per lead is high because clicks are expensive or nobody clicks, the CPM, CPC and CTR calculator helps find which.
If your cost per customer is creeping up and you can't see why, that's the kind of thing I dig into in Google Ads management and B2C performance marketing work. Some examples are on the case studies page.
FAQ
CPA and cost per lead questions
How do you calculate cost per lead?
Cost per lead = ad spend ÷ number of leads, for the same period. $1,500 of spend and 40 leads is $37.50 per lead.
What is the difference between CPA and CPL?
CPL counts leads: enquiries, calls, form fills. CPA counts whatever you define as the acquisition, often a sale or a purchase. For an online store CPA usually means cost per purchase; for a service business a lead is not yet a customer, so CPA and CPL are different numbers.
What is customer acquisition cost (CAC)?
What it costs to win one paying customer. For a lead business: (ad spend + other marketing costs) ÷ customers won. If 40 leads close at 25%, you won 10 customers, so $1,500 of spend gives a CAC of $150.
What is a good cost per lead?
One you can afford after the close rate. A $90 lead is cheap for a firm that closes half its leads on $5,000 cases and expensive for a salon selling $60 treatments. Work out the CAC and compare it with what a customer is worth to you.
Is cost per result in Meta Ads Manager the same as CPA?
It is the CPA for whatever result the campaign is optimising for: leads, purchases, messaging conversations or landing page views. Check the result type in the column before comparing campaigns, because a cheap cost per result for link clicks is not comparable to a cost per purchase.
Can I use this for WhatsApp or Messenger leads?
Yes. Pick Leads and enter the number of real conversations. I only count chats where the person asked about the service, not greetings that went nowhere, otherwise the cost per lead looks better than it is.
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