eCPM Calculator

eCPM = (total earnings ÷ total impressions) × 1,000. The “effective” prefix distinguishes it from a quoted CPM price: eCPM back-calculates what you actually earned per thousand impressions after the mix of pricing models, fill rates, and auctions plays out. Three factors dominate the number: ad format (rewarded video commands the most, banners the least), user geography (tier-1 markets pay several times tier-3), and seasonality — advertiser budgets surge in Q4 and reset in January, routinely swinging eCPMs 30–50% between late December and early January.

Typical ranges illustrate the spread: US iOS rewarded video often lands around $10–25 eCPM, interstitials $5–15, and banners $0.50–2 — with the same formats earning a fraction of that in emerging markets. This is why a blended eCPM is nearly useless for decisions: always segment by format and country before comparing networks or judging a change.

eCPM prices impressions, not users — so maximizing it blindly is a classic trap. Cranking up interstitial frequency can raise impressions while lowering eCPM (more supply, lower-value later impressions) yet still increase total revenue; but aggressive frequency also damages retention, which quietly destroys more value than the extra impressions add. The metric that reconciles these forces is ad ARPDAU (ad revenue per daily active user) = impressions per DAU × eCPM ÷ 1,000 — optimize that, with retention as a guardrail, and let eCPM be a diagnostic input.

For projections, the honest form is revenue = DAU × impressions-per-DAU × eCPM ÷ 1,000, with each factor estimated separately — because scaling users usually shifts the geography mix down-market, which drags eCPM below your current blended figure. A projection that holds today’s eCPM constant while tripling users in low-eCPM markets will overshoot badly.