Metric wiki
CPM vs CPC
By Oliver Wakefield-Smith · updated October 2026
The short answer
CPM prices exposure; CPC prices response. Which is cheaper is not an opinion, it is a click-through-rate crossover: divide the CPM by clicks per thousand and you have the effective CPC you are already paying. At Meta's December 2025 tracker average ($10.02) and a 1% CTR, an impression buy costs $1.00 per click.
effective CPC = CPM ÷ (CTR × 1,000)
$10.02 CPM at 0.5% CTR = $2.00 per click
$10.02 CPM at 1.0% CTR = $1.00 per click
$10.02 CPM at 2.0% CTR = $0.50 per click
Rate anchor: Gupta Media tracker, Meta (Facebook + Instagram) average for December 2025, retrieved October 2026. CTRs are stated inputs spanning the plausible display-to-social range.
Reading the crossover
The break-even rule: CPM buying beats a quoted CPC whenever your effective CPC computes below it, which happens exactly when CTR exceeds CPM ÷ (CPC × 1,000). Strong creative with proven CTR makes impression buying a discount; weak or unproven creative makes CPC a hedge, because the platform absorbs the click risk. That hedge is priced in, which is why platforms happily sell both.
Which objectives should bid which
- Bid CPM for awareness and reach goals, retargeting pools with known response, and any campaign where the view itself is the product.
- Bid CPC when traffic is the deliverable and your CTR is unproven; you pay only for what lands.
- Know the machinery anyway:Google's auction ranks CPC bids by expected impressions-to-clicks anyway, effectively converting your CPC bid into an eCPM to compare against impression bids. You are in the impression auction either way; the question is who carries the CTR risk.
Continue down the funnel: CPM vs CPA extends this cascade to acquisitions. Reduce the input: how to lower CPM. Run your own crossover in the calculator.