Learn how to CPM: how to calculate impressions from CPM and budget, how to compute CPM, and how to apply all 3 variants of the CPM formula — with a free calculator.
How to CPM depends on what you need to calculate. There are three scenarios — each uses a different variant of the CPM formula. Here is how to CPM for each case.
To compute CPM, take your total cost, divide by total impressions, and multiply by 1,000. Example: $400 cost ÷ 200,000 impressions × 1,000 = $2.00 CPM. Use the "Calculate CPM" tab above to compute CPM instantly.
To calculate impressions from CPM and budget: divide your budget by CPM, then multiply by 1,000. Example: $500 budget ÷ $5 CPM × 1,000 = 100,000 impressions. Use the "Find Impressions" tab above.
To calculate cost from CPM and impressions: multiply CPM by impressions, then divide by 1,000. Example: $5 CPM × 500,000 impressions ÷ 1,000 = $2,500 cost. Use the "Find Cost" tab above.
Knowing how to calculate impressions from CPM and budget is essential for campaign planning. Here is the exact method with real examples.
To calculate impressions from CPM and budget, use this formula: Impressions = (Budget ÷ CPM) × 1,000. This tells you exactly how many times your ad will be shown given your spend and CPM rate.
Example 1: Budget = $200, CPM = $4
Impressions = ($200 ÷ $4) × 1,000 = 50,000 impressions
Example 2: Budget = $1,000, CPM = $5
Impressions = ($1,000 ÷ $5) × 1,000 = 200,000 impressions
Example 3: Budget = $10,000, CPM = $20
Impressions = ($10,000 ÷ $20) × 1,000 = 500,000 impressions
Calculating impressions from CPM and budget lets you forecast your campaign reach before spending. Media buyers use this calculation to compare platforms — if Google gives you 200,000 impressions for $1,000 while Facebook gives you 400,000, Facebook has a lower CPM and better reach efficiency for that budget.
Use the "Find Impressions" tab in the calculator above to calculate impressions from CPM and budget in seconds — no manual math needed.
Here is exactly how to compute CPM step by step — with examples for every platform and campaign type.
To compute CPM, apply the standard formula: CPM = (Total Cost / Total Impressions) × 1,000. Here is how to compute CPM for the most common advertising scenarios.
You spent $300 on a Google Display campaign that generated 150,000 impressions. How to compute CPM: ($300 ÷ 150,000) × 1,000 = $2.00 CPM. This means you paid $2 for every 1,000 times your display ad was shown.
You spent $800 on YouTube ads and received 80,000 ad impressions. How to compute CPM: ($800 ÷ 80,000) × 1,000 = $10.00 CPM. YouTube CPM is typically higher than display because video ads command premium rates.
Your Facebook campaign cost $500 and delivered 250,000 impressions. How to compute CPM: ($500 ÷ 250,000) × 1,000 = $2.00 CPM. Social CPMs vary widely by targeting, audience size, and competition.
As a website publisher, you earned $150 from 50,000 ad impressions. How to compute CPM from revenue: ($150 ÷ 50,000) × 1,000 = $3.00 CPM. Publishers use this to evaluate which ad networks pay the most per impression.
Compute CPM when your goal is reach and brand awareness. If your goal is clicks, compute CPC (Cost Per Click) instead. If your goal is conversions, compute CPA (Cost Per Acquisition). Each metric serves a different purpose — CPM is the right metric when impressions are your primary KPI.
Answers to the most common questions about how to CPM, how to calculate impressions from CPM and budget, and how to compute CPM.