Impressions calculator

How many impressions a budget buys at each channel's CPM — and what frequency that works out to.

Runs entirely in your browser — nothing is uploaded, nothing is stored. Updated 2026-09-30.

Impressions = budget ÷ CPM × 1,000. $5,000 at an $8.50 CPM buys about 588,235 impressions; the same $5,000 at $2.40 buys more than two million.

That is why an impressions forecast has to be built channel by channel: the CPM on display inventory, a social feed and a video placement can differ by a factor of five, and a single blended CPM hides which part of the budget is doing the reaching. Add a row per channel below for the total, and use the second panel to turn impressions and unique reach into average frequency — the number that tells you whether you are reaching more people or the same people again.

Why one blended CPM gives the wrong forecast

With the seed numbers above, $5,000 buys about 900,000 impressions, a blended CPM of $5.55. Move $1,000 from display to YouTube and the budget is unchanged but the forecast drops by roughly 330,000 impressions, because display at $2.40 and YouTube at $11.00 are not the same price. A plan built on the blended $5.55 would not see that.

The same arithmetic runs the other way on the CPM calculator, which turns spend and impressions into the rate you actually paid.

Impressions, reach and frequency

Impressions count every time an ad is shown; reach counts the people who saw it at least once; frequency is the first divided by the second. A forecast of 900,000 impressions says nothing about how many people that is until you estimate reach — at a frequency of 2.5 it is 360,000 people, at a frequency of 6 it is 150,000.

Platforms report reach as de-duplicated people inside their own walls, so reach cannot be added across platforms: the same person on Meta and YouTube is counted by both. Frequency is therefore a per-platform number, and the cross-channel figure is an estimate at best.

Where the forecast goes wrong

CPM is an auction price, not a rate card. It rises as you narrow the audience, as competitors bid for the same inventory and in the weeks before seasonal peaks, so a forecast built on last month's CPM is a ceiling on impressions, not a promise. Delivery also depends on the audience being large enough: a small audience runs out of new people and pushes frequency up before it pushes impressions up.

Plan on the CPM each channel actually delivered for a similar audience, re-check after the first week, and treat the gap between forecast and delivered impressions as the market telling you the audience is more contested than you assumed.

Computing this from your own accounts

Every calculator on this page takes numbers you typed. The version that keeps working is the one that reads them from the accounts themselves — which is what TableBI is: connect Google Ads, Meta Ads, GA4 or Search Console once, and cpm() becomes a macro you can query from your terminal.

# connect once, then the metric is a standing query
tablebi connect google_ads
tablebi connect meta_ads   # beta: your own or test ad accounts

tablebi ask "WITH w AS (SELECT MAX(date) AS anchor FROM metrics)
   SELECT platform, cpm(SUM(cost), SUM(impressions)) AS cpm
   FROM metrics, w WHERE date > w.anchor - 30
   GROUP BY platform ORDER BY cpm DESC"

# pin the answer to a URL that refreshes itself
tablebi pin --title "impressions calculator by channel"
→ https://you.tablebi.com/d/dsh_…

The pinned answer is a live URL that refreshes on its own — here is one running now. No hosted model does the reasoning; your own Claude Code or Codex drives the CLI, which is why there is no inference bill attached to it.

Questions people ask about impressions calculators

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