What is an impression?
An impression is one showing of your ad or post on someone's screen. The same person can create several impressions. For the difference from reach, see impressions vs reach.
Impressions formula
Impressions = budget ÷ CPM × 1,000
Example: a 500 budget at an 8 CPM buys 62,500 impressions. At a frequency of 2, that reaches about 31,250 people.
How to use it to plan a campaign
Use your own past CPM from Ads Manager if you have it. If not, run a small test first, then plan with the real number. To check what you paid, use the CPM calculator; to see how often people saw your ads, use the ad frequency calculator.
Impressions on Instagram, TikTok and X
Organic posts also show impressions (or views) in each app's analytics. They are not bought with CPM, but the same idea applies: impressions divided by reach tells you how often each person saw the post.
Impressions calculator from CPM
Impressions = budget ÷ CPM × 1,000
CPM is the cost of 1,000 impressions, so dividing your budget by it and multiplying by 1,000 gives the impressions you can buy. Example: $500 at a $10 CPM buys 500 ÷ 10 × 1,000 = 50,000 impressions. If you already know your impressions and want the CPM, use the CPM calculator.
Impressions on Instagram and TikTok
On Instagram, impressions (now often called views) count every time your post or Reel is shown, including repeat views by the same person. TikTok reports video views instead. For organic posts you can't buy impressions, so use the platform's own figure and divide engagement by it with the engagement rate calculator.
How to use this calculator
Enter ad budget, CPM, campaign length and expected frequency. The result updates as you type, so you do not need to press Calculate after each change. Use Copy result to paste the figure into a report, or Share link to send the calculator with your numbers already filled in.
Related calculators
You may also want the CTR Calculator (Click-Through Rate), Email CTR and Click-to-Open Rate Calculator, CPM Calculator. Browse everything in ad cost metrics calculators.
Frequently asked questions
How many impressions does $100 get?
At a $5 CPM, 20,000 impressions; at $10, 10,000. Enter your CPM for your number.
Is reach the same as impressions?
No. Reach counts people; impressions count showings.
How do you calculate impressions?
For paid ads, divide the budget by the CPM and multiply by 1,000. For organic posts, read impressions from the platform's analytics.
How many impressions is good?
It depends on your audience size. A useful check is impressions divided by followers: if it's well below 1, most followers are not seeing your posts.
Results are estimates based on the numbers you enter and are not financial advice.