Worked scenario
Reach vs frequency at a fixed budget
By Oliver Wakefield-Smith · updated October 2026
The short answer
The site's second formula: impressions equal reach times frequency. A $5,000 budget at Meta's December 2025 tracker average of $10.02 buys about 499,002 impressions no matter what; frequency decides whether that is 499,002 people once or 99,800 people five times.
impressions = reach × frequency
$5,000 ÷ $10.02 × 1,000 = 499,002 impressions to allocate
Rate: Gupta Media tracker, Meta (Facebook + Instagram) average for December 2025, retrieved October 2026.
| Frequency cap | Net reach (people) | Reads as |
|---|---|---|
| 1x | 499,002 | maximum breadth, zero reinforcement |
| 2x | 249,501 | the conventional awareness zone |
| 3x | 166,334 | the conventional awareness zone |
| 5x | 99,800 | reinforcement, at a real cost in people |
| 8x | 62,375 | saturation territory; check for fatigue |
Neither platform publishes an optimal frequency; the effective number depends on creative, category and cycle length. What is documented: both major platforms ship frequency caps as a control because uncapped delivery drifts toward cheap repeat impressions, and repeat impressions past attention are where budgets go to die quietly.
When paying a fixed CPM for reach beats the auction
Meta's reach and frequency buying quotes a locked CPM upfront in exchange for committing budget, with frequency controls built in. You typically pay some premium over the auction's cheapest path; what you buy is predictability, which matters for launches and date-bound campaigns where under-delivery is worse than overpaying slightly per thousand. For always-on performance spend, the auction usually wins.
Frequency saturation is cause three at why is my CPM so high. The budget side of this trade is worked in the $1,000 test budget, the base formula at /formula, and your own numbers go in the calculator.