About the CPA Calculator
This CPA calculator works out cost per acquisition — how much you paid in advertising for each sale, sign-up, lead or install. Enter your ad spend and the number of conversions and it returns CPA instantly; the same math gives cost per lead (CPL) when your conversion is a form fill or booked call.
Add the clicks the campaign received and the calculator also shows cost per click and click-to-conversion rate, so you can tell whether a high CPA comes from expensive traffic or from a landing page that does not convert. Enter what each conversion is worth and a target CPA to see ROAS, profit per conversion and how far you are above or below target.
It suits PPC managers, lead-generation agencies, app marketers and small business owners checking Google Ads, Meta, LinkedIn or TikTok results. Use spend and conversions from the same platform and date range.
With the default inputs, the cost per acquisition (cpa) is $40.00. Change any value above to recalculate instantly.
How to use the cpa calculator
- 1Enter total ad spend for the campaign or period.
- 2Enter the number of conversions — sales, leads, sign-ups or installs.
- 3Add clicks to see cost per click and conversion rate.
- 4Enter what a conversion is worth and your target CPA.
- 5Read your CPA and check whether it beats the target and the conversion value.
Formula and method
Cost per acquisition is total ad spend divided by the number of conversions in the same period. It can also be written as cost per click divided by the click-to-conversion rate, which shows the two levers: cheaper clicks or a better-converting landing page.
If you enter a value per conversion, ROAS is (value × conversions) ÷ spend and profit per conversion is value minus CPA. The comparison with target CPA is (CPA − target) ÷ target, and conversions needed at target is spend ÷ target CPA, rounded up. Cost per lead (CPL) uses the identical formula with leads as the conversion.
- CPA
- Cost per acquisition (or per lead)
- CPC
- Cost per click = spend ÷ clicks
- Conversion rate
- Conversions ÷ clicks
Worked examples
$5,000 spend, 125 sales
$5,000 ÷ 125 = $40 per sale, 20% under the $50 target. Clicks cost $1.25 each and 3.125% of them converted. With each sale worth $80, ROAS is 2x and the campaign returns $5,000 more than it cost.
B2B lead generation: cost per lead
$3,600 bought 48 leads, a cost per lead of $75 — 25% above the $60 target. At $4 per click and a 5.33% conversion rate, hitting target would require 60 leads from the same budget, so the landing page conversion rate needs to rise to about 6.7%.
Campaign where CPA exceeds order value
$2,400 ÷ 30 = $80 per sale, but each sale is only worth $65, so every conversion loses $15 and the campaign is $450 short. The CPA is double the $40 target.
Frequently asked questions
How do you calculate CPA?+
Divide your total advertising cost by the number of conversions. If you spent $2,000 and got 50 customers, CPA is $2,000 ÷ 50 = $40. Use spend and conversions from the same campaign and date range.
What is the difference between CPA and CPL?+
The formula is the same; only the conversion differs. CPA usually refers to a paying customer or sale, while cost per lead (CPL) counts form fills, calls or sign-ups that still need to be converted into customers.
What is a good CPA?+
A good CPA is below the profit a conversion brings you — for e-commerce, below the margin on the order (or lifetime value if customers return). Industry averages vary widely, so your own margin is the benchmark that matters.
How can I lower my CPA?+
Either lower cost per click (better targeting, higher quality scores, negative keywords) or raise conversion rate (faster, clearer landing pages, stronger offers). Because CPA = CPC ÷ conversion rate, a 20% gain in either reduces CPA noticeably.
Is CPA the same as customer acquisition cost (CAC)?+
Not quite. CPA usually covers media spend for a specific campaign. CAC is broader, adding salaries, tools, agency fees and all marketing and sales costs divided by new customers across the business.