CPM, CPC and CPA calculator
Advertising prices come as a cost per thousand impressions (CPM), per click (CPC) or per acquisition (CPA). Enter the ad spend and what it bought to get all three rates, or enter a rate and a budget or volume to find the missing number.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Enter the ad spend, or leave it empty to have it calculated.
- For impressions, clicks and conversions, enter either the count or its rate (CPM, CPC, CPA) and leave the other empty.
- The calculated values are shown at the top; click-through and conversion rates appear when both counts are known.
How it works
The cost is shared by three groups:
- CPM = cost ÷ impressions × 1,000; impressions = cost ÷ CPM × 1,000.
- CPC = cost ÷ clicks; clicks = cost ÷ CPC.
- CPA = cost ÷ conversions; conversions = cost ÷ CPA.
If the cost is empty it comes from the first group with both a count and a rate: cost = count × rate (÷ 1,000 for CPM). CTR = clicks ÷ impressions; conversion rate = conversions ÷ clicks.
Worked example
A campaign spent 500 for 100,000 impressions, 1,500 clicks and 60 sales:
- CPM = 500 ÷ 100,000 × 1,000 = 5.
- CPC = 500 ÷ 1,500 ≈ 0.3333.
- CPA = 500 ÷ 60 ≈ 8.3333.
- CTR = 1,500 ÷ 100,000 = 1.5%; conversion rate = 60 ÷ 1,500 = 4%.
Tips
- A low CPM is not a good deal if few people click; compare campaigns on CPA where you can.
- Use the same period and attribution settings for spend and conversions.
- To see revenue against spend, use the ROAS calculator.
Frequently asked questions
How is CPM calculated?
CPM = cost ÷ impressions × 1,000. Spending 500 on 100,000 impressions is a CPM of 5: each thousand impressions cost 5.
What are CPC and CPA?
CPC = cost ÷ clicks, the average price of a click. CPA = cost ÷ conversions, the average price of a sale, sign-up or other goal.
How do I estimate the budget?
Leave the ad spend empty and enter a count with its rate. 250,000 impressions at a CPM of 8 cost 250,000 × 8 ÷ 1,000 = 2,000. The other rates then use that cost.
How many impressions will my budget buy?
Enter the budget and the CPM and leave impressions empty: impressions = budget ÷ CPM × 1,000. The same works for clicks from a CPC and conversions from a CPA.
Why does it say to leave a field empty?
Within each group of cost, count and rate, two values fix the third. If all three are filled in they may contradict each other, so one must be left for the calculator.