CPM Calculator (Cost Per Thousand Impressions)
Calculate and compare CPM across advertising channels from cost and impressions. Find the cheapest reach. Runs in your browser.
CPM by channel
| Channel | CPM |
|---|---|
| $6.25 | |
| Google Display ✓ lowest | $4.17 |
| Newsletter | $16.00 |
CPM (cost per mille) = cost ÷ impressions × 1,000 — the price to reach 1,000 people. Lower CPM is cheaper reach, but compare alongside relevance and conversion: a cheap CPM that doesn't convert is worse than a pricey one that does. CPM measures reach cost, not results (see CAC for cost per customer). Informational.
About this tool
CPM — cost per mille, or cost per thousand impressions — is the standard way to compare the cost of reach across advertising channels. It is simply the spend divided by impressions, times one thousand. This calculator computes CPM for any number of channels side by side and highlights the cheapest reach. It is useful for media planning and for sanity-checking quotes, but the page is clear about its limits: CPM measures the cost to be seen, not the cost to get results. A channel with a low CPM but poor targeting or low conversion can be far more expensive per actual customer than a pricier, better-converting channel — which is why CPM should be read alongside click-through, conversion rate, and ultimately cost per acquisition (CAC). Use CPM to compare reach efficiency at the top of the funnel, then judge channels on what they actually deliver downstream. Everything is computed in your browser.
How to use it
- Enter each channel's ad spend and impressions delivered.
- Read the CPM for each; the lowest is highlighted.
- Compare reach cost across channels.
- Then weigh CPM against conversion and CAC — cheap reach isn't always cheap results.
Frequently asked questions
- How is CPM calculated?
- CPM = (cost ÷ impressions) × 1,000. If you spend $500 for 80,000 impressions, CPM = 500 ÷ 80,000 × 1,000 = $6.25 — the cost to reach one thousand people.
- What is a good CPM?
- It varies enormously by channel, audience, and targeting — display can be a few dollars, premium video or niche B2B far higher. There is no universal "good" number; compare within your channels and against your conversion economics.
- Is the lowest CPM always best?
- No. Cheap reach is worthless if it does not convert. A low-CPM channel with poor targeting can cost more per customer than a high-CPM channel that converts well. Use CPM for reach efficiency, but judge channels by downstream results.
- How does CPM relate to CPC and CPA?
- CPM is cost per 1,000 impressions (reach); CPC is cost per click (engagement); CPA/CAC is cost per acquisition (result). They sit progressively deeper in the funnel. CPM is the broadest and least outcome-tied of the three.
- Why compare channels on CPM?
- It normalizes spend to a per-impression basis so channels with different budgets and reach are comparable. It is the starting point of media planning — then layer in targeting quality and conversion to pick winners.
- Is anything uploaded?
- No. The calculation runs entirely in your browser.