CPM Calculator

Divides your total ad spend by the number of impressions and scales the result to a per-1,000 basis, giving you the CPM (cost per mille) — what you paid, on average, to show your ad 1,000 times.

Enter your total ad spend and the number of impressions the campaign delivered. The CPM updates immediately as you type either value.

With ad spend of $500 and 100,000 impressions (the pre-filled defaults), CPM = (500 ÷ 100,000) × 1,000 = $5.00 — meaning every 1,000 times the ad was shown cost $5.00 on average.

CPM = (ad spend ÷ impressions) × 1,000. "Mille" is Latin for "thousand," which is where the M in CPM comes from — the same convention used across print, TV, radio and digital display advertising for comparing prices on a per-audience basis.

CPM charges (or measures cost) per impression regardless of whether anyone clicks, which suits brand-awareness campaigns where reach matters more than direct response. CPC (cost per click) only counts clicks, and click-through rate (CTR) measures what share of impressions turned into clicks — the three metrics together show whether a cheap CPM is actually translating into engagement, or just cheap, unseen reach.

CPM alone says nothing about ad quality, viewability, fraud, or whether the audience matched your target — a very low CPM from a low-quality placement can perform worse overall than a higher CPM on a well-targeted, viewable placement. Use it to compare like-for-like inventory, not as a standalone measure of campaign success.

CPM is a standard media-buying metric used across the advertising industry, defined the same way by ad platforms, agencies and measurement bodies. The calculation runs entirely in your browser; the numbers you enter are never sent to a server.