Cost Per Impression Calculator

What is cost per impression?

Cost per impression — sometimes shortened to CPI — is what an advertiser pays for a single impression of an ad. An impression is counted each time the ad is served or displayed to someone, so cost per impression is the most granular measure of what your ad exposure costs.

In digital marketing it is the base unit of impression-based pricing — as opposed to click-based pricing — where you pay to be seen whether or not anyone clicks. Because one impression typically costs only a fraction of a cent, the industry more often quotes CPM (the cost of 1,000 impressions). Cost per impression comes into its own when you need precise, per-unit economics rather than a headline rate.

Impression vs pageview — why the two rarely match

This is the single most common reason two people looking at the same campaign quote different numbers, and it is worth getting straight before you compare anything.

• An impression is one ad being shown once.
• A pageview is one page being loaded once.

Most pages carry more than one ad, so a single pageview usually produces several impressions. A page with three ad slots turns 10,000 pageviews into roughly 30,000 impressions — which means the cost per impression is about a third of the cost per pageview, for exactly the same traffic and exactly the same spend.

Two consequences follow. As an advertiser, never compare an impression-based cost against a pageview-based one without checking how many ad slots sit on the page. And as a publisher, the same gap is why your earnings per 1,000 pageviews normally look higher than your earnings per 1,000 ad views — the distinction we cover in CPM vs RPM.

One more wrinkle: an impression means the ad was served, not necessarily that anyone saw it. Platforms report viewable impressions separately, counting only ads that actually entered the screen. If your figures disagree with a platform's, that is usually the reason.

How to calculate cost per impression

To calculate cost per impression, divide the total cost of your campaign by the number of impressions it delivered:

Cost per impression = Cost ÷ Impressions

In two steps: take the total amount spent, then divide it by the total number of impressions. For example, $10,000 spent for 1,000,000 impressions gives a cost per impression of $0.01 — one cent.

Because the formula links three values, you can rearrange it to solve for whichever one you are missing — which is exactly what the calculator above does:

• Find cost per impression — Cost ÷ Impressions ($5,000 ÷ 2,000,000 = $0.0025)
• Find Cost — Cost per impression × Impressions ($0.004 × 500,000 = $2,000)
• Find Impressions — Cost ÷ Cost per impression ($8,000 ÷ $0.005 = 1,600,000)

A worked example

Suppose you spend $10,000 and earn 1,000,000 impressions. Your cost per impression is:

$0.01 = $10,000 ÷ 1,000,000

That is one cent per impression, equivalent to a $10.00 CPM. Working the other way: if your cost per impression is $0.008 and you have a $10,000 budget, that budget buys 1,250,000 impressions ($10,000 ÷ $0.008) — a quick way to check the reach a budget can deliver.

How to use this calculator

1. Choose which value to solve for — cost per impression, cost, or impressions.
2. Enter the two values you already know. Results update instantly as you type.
3. Switch currency if you're planning in something other than dollars.
4. Use Copy shareable link to send the exact scenario to a colleague — the numbers are saved in the URL.

What's a good cost per impression?

There is no universal "good" cost per impression — it depends on platform, audience, format and season, and because the per-impression figure is so small it is almost always judged as a CPM. As a quick orientation, $0.01 per impression equals a $10 CPM, and $0.005 equals a $5 CPM. Broad display sits at the low end, while tightly targeted social or video runs higher.

Rather than chase a single number, compare against real rates for your channel. Our advertising benchmarks show typical CPM by industry for Google and Meta, plus CPM by country.

Cost per impression vs CPM

Cost per impression and CPM measure identical things — they only differ by a factor of 1,000:

• CPM = Cost per impression × 1,000
• Cost per impression = CPM ÷ 1,000

CPM stands for cost per mille — Latin for "per thousand" — so a "CPM rate" is simply the cost of 1,000 impressions, and "cost per thousand impressions" means the same thing. In advertising, CPM is the standard way costs are quoted because a single impression costs a fraction of a cent and 1,000-impression pricing keeps the numbers readable. So a $0.01 cost per impression is the same as a $10.00 CPM. If you think in CPM day to day, the CPM calculator is the companion tool; use this page when you specifically need the per-impression figure.

When is cost per impression used?

Cost per impression matters most where per-unit economics are the point:

• Programmatic and real-time bidding — automated ad buying where each single impression is bid on and bought in a fraction of a second.
• Publisher and ad-network economics — comparing what an impression costs to buy against what it earns.
• Brand-awareness campaigns — measured on reach and exposure rather than clicks.

It sits opposite click-based pricing like cost per click (CPC): impression pricing charges you to be seen, while click pricing charges you only when someone acts. Which model is better depends on whether your goal is awareness or response.