Reach and Frequency

Reach is the number of people, or more precisely the number of accounts, that saw an ad at least once during a given period. Frequency is the average number of times each person in that group saw the ad.

What are reach and frequency?

These two metrics break impressions into two parts: how many people, and how many times each.

Frequency = Impressions / Reach

For example, 500,000 impressions seen by 200,000 people gives a frequency of 2.5. Those same 500,000 impressions could also mean 500,000 people seeing the ad once, or 50,000 people seeing it ten times. The two outcomes are completely different, yet the impressions and the CPM are identical.

Reach on ad platforms is an estimate. Meta calculates reach from sampled data (Meta, Glossary of reservation terms). In Vietnam, TikTok’s ad tools put its ad audience at 102.9% of the population aged 18 and over (DataReportal Digital 2026 Vietnam, November 2025). The figure tops 100% because the platform counts accounts, not people.

What is the optimal frequency?

No single number is right for every campaign. A few reference points to start from:

• TikTok recommends an average frequency of 3 times per week. Its global brand lift data from January 2025 to February 2026 showed that level was the most effective for lifting ad recall and awareness (TikTok Brand Basics, May 2026).
• Meta notes that frequency per ad set usually sits between 1 and 2, and can go higher depending on budget, audience and schedule. A brand that customers already know needs fewer exposures than a new one.
• If results fall while frequency rises, your audience has ad fatigue. That is the time to change the creative or widen the audience. Adtek’s Vietnamese-language article on Meta advertising in 2026 explains how Meta picks creative today.

Frequency cap vs target frequency

A frequency cap sets a ceiling: nobody sees the ad more than N times in X days. Target frequency sets the weekly average you want, and the system adjusts delivery to reach it.

A cap favors breadth, so most people see the ad only 1 to 2 times. Target frequency favors steadier repetition, and in exchange you get lower reach for the same budget.

Hypothetical example in Vietnam

A coffee chain is opening 5 new stores in Hanoi. Its target audience is 400,000 accounts within a 3 km radius, and the budget buys 2.4 million impressions over 4 weeks.

• Option 1, capped at 2 times every 7 days: reaches about 340,000 people (85% of the audience), with a frequency of about 7 across the whole flight.
• Option 2, no cap: impressions pile up on 150,000 people who engage easily, frequency climbs to 16, and more than half the audience never sees the ad at all.

For announcing store openings, option 1 is the better fit.

Reach vs impressions vs the Reach objective

Impressions count how many times the ad was shown, so one person seeing it three times equals three impressions. Reach counts people. The Reach objective is a way for the system to optimize delivery, while reach is a reporting metric available in every campaign. In October 2023, Meta renamed its “Reach and frequency” buying type to “Reservation”. The objective that uses reach as its main yardstick is the brand awareness objective.

Frequently asked questions

Can you add up reach across campaigns?

No. A person who saw both campaigns gets counted twice. To get combined reach, select the campaigns together in your ads manager and look at the deduplicated reach.

Is a frequency of 10 too high?

It depends on the time frame. Ten exposures in 2 days is high. Ten in 2 months is not necessarily a problem.

If you need a reach and frequency plan for an awareness campaign, or want to check whether your budget is concentrated on too few people, Adtek’s ads team can help. Get in touch via our contact page.