How to Calculate Cost Per Impression (CPI)

Advertisers use the cost per impression formula to measure the efficiency of their campaigns and manage budgets effectively. By knowing the CPI, you can compare how much you spend to reach your audience across different platforms or campaigns.

The cost per impression formula helps marketers control spending by showing how much exposure they get for every dollar spent. Understanding this metric makes it easier to allocate budgets, forecast ROI, and identify which ad placements deliver the best value.

Yes. Using the cost per impression formula allows advertisers to evaluate performance across channels, audiences, or ad creatives. A lower CPI usually means your campaign is reaching more people efficiently, helping you make smarter optimization decisions.

You can calculate the cost per impression by using the cost per impression formula.  The formula is: CPI = Total ad cost / Total impressions.

Cost Per Impression (CPI) measures how much it costs to expose one viewer to your ad. It’s used to gauge the expense of digital advertising campaigns and helps advertisers understand their investment relative to audience reach.

The above CPI Calculator can help you determine the efficiency of your advertising budget. Consider using a cost per impression calculator to help with:

• Budget Allocation: Determine how much you are willing to spend for visibility.
• Campaign Evaluation: CPI provides a metric to evaluate the financial efficiency of an advertising campaign.
• Performance Measurement: Measure and compare the performance and impact of different campaigns.
• Financial Forecasting: Predict future costs related to ad impressions and plan your marketing accordingly.
• Targeting Efficiency: CPI can help assess the efficiency of targeting methods.
• Brand Awareness: CPI reflects the cost of exposing your brand to a large audience. Lower CPI means more exposure per dollar spent, which can enhance brand recognition.
• Benchmarking: CPI is a standardized metric that can be used to benchmark against industry standards or historical performance.

A CPM impressions calculator lets you input the total cost of your ad campaign and the number of impressions to calculate the cost per thousand impressions. You can still use an advertising cost per impression calculator to determine CPM. Simply multiply your CPI by 1,000.

Several factors can influence the cost per impression of ads. This includes the advertising platform used, the target audience's competitiveness, the ad's quality and relevance, and the timing of the campaign.

That’s why it’s important to use your CPI alongside other measurements and data to best understand how your campaign is performing.

CPI (Cost Per Impression) measures the cost of a single ad impression. The formula is:

CPI = Total Ad Cost ÷ Total Impressions

For example, if you spend $100 on 10,000 impressions, your CPI is $0.01.

CPM (Cost Per Mille) calculates the cost per thousand impressions, making it easier to compare campaigns where impressions are in the thousands or millions. To calculate CPM, you take the CPI and multiply it by 1,000:

CPM = (Total Ad Cost ÷ Total Impressions) × 1,000

So in the same example, your CPM would be $10.

If you’re wondering “how do you calculate a CPM” or “how to calculate a CPM,” the key difference is scale: CPM gives you a standardized cost per thousand views, while CPI shows the exact cost per one impression.

To calculate CPM, divide your total ad spend by the total number of impressions, then multiply the result by 1,000.

Formula:

CPM = (Total Ad Cost ÷ Total Impressions) × 1,000

For example, if you spend $500 on 200,000 impressions, your CPM would be $2.50. This means you’re paying $2.50 for every 1,000 times your ad is shown.

1. Add up your total ad spend for the campaign.
2. Count the total number of impressions your ad received.
3. Divide the total cost by the total impressions.
4. Multiply that number by 1,000 to find the cost per thousand impressions (CPM).

Example: $250 ÷ 50,000 impressions = $0.005 CPI. Multiply by 1,000, and your CPM is $5.