CPA Calculator
You're paying $25.00 for each of 160 conversions.
What is CPA?
CPA (cost per acquisition) is ad spend divided by conversions. Spend 4,000 for 160 conversions and your CPA is 25: that is the price of each action you paid to make happen.
A conversion is whatever you set it to be, from a newsletter signup to a checkout. That flexibility means a CPA only has meaning once you know which action it counts.
Lower is better, but only against value. A 25 CPA is a bargain for a high-value sale and far too expensive for a low-intent lead, so always read CPA next to what the conversion is worth.
How to calculate CPA
CPA = Ad spend ÷ Conversions
- Define the conversion. Decide which action counts: a sale, a qualified lead, a signup. CPA is only comparable when the action is the same.
- Total the ad spend. Add up what you paid the platform over the period you are measuring.
- Count the conversions. Count the conversions of that one type recorded in the same period.
- Divide spend by conversions. Ad spend divided by conversions is your CPA. 4,000 divided by 160 is a CPA of 25.
Worked example
A campaign spends 4,000 and records 160 conversions over the same period.
| Ad spend | $4,000 |
|---|---|
| Conversions | 160 |
| Result | $25.00 CPA |
Each conversion cost 25 to produce. Whether that is good depends on the action: profitable for a sale with healthy margin, expensive for a top-of-funnel signup.
How to improve CPA
- Raise conversion rate on the landing page so the same clicks produce more conversions at the same spend.
- Tighten targeting toward the audiences and keywords that convert, cutting spend that never reaches the action.
- Improve ad and offer relevance to lower CPC, which flows straight through to a lower CPA.
- Match the conversion you optimize for to real value, so a falling CPA reflects better economics, not just cheaper, weaker actions.
Frequently asked questions
- What is CPA and how do you calculate it?
- CPA (cost per acquisition) is your ad spend divided by the number of conversions it produced. Spend 4,000 and get 160 conversions and your CPA is 25. A conversion can be any action you are paying for: a signup, a lead, a download or a sale.
- What is a good CPA?
- There is no universal good CPA, because it only makes sense against what a conversion is worth to you. A 25 CPA is excellent for a 500 sale and terrible for a free newsletter signup. Judge it against the value of the action and the margin behind it, not a fixed number.
- Is CPA the same as CPC?
- No. CPC (cost per click) is what you pay for a visit; CPA is what you pay for a completed conversion. The two are linked by conversion rate: CPA is roughly CPC divided by the share of clicks that convert, so a 0.38 click that converts at 3% costs about 12.50 per conversion.
- What is the difference between CPA and CAC?
- CPA measures the cost of one conversion event, which may sit anywhere in the funnel. CAC (customer acquisition cost) measures the cost of a paying customer specifically, and often folds in salaries and tools, not just ad spend. CPA on a lead is usually far lower than the CAC for the customer that lead eventually becomes.