Reach vs frequency comes down to breadth versus depth. Reach is the number of unique people who saw your ad at least once in a set period, and frequency is the average number of times each of those people saw it. Multiply the two and you get impressions.
Every media budget is a trade between them. The same $6,000 can show an ad to 2 million people twice or 800,000 people five times. This guide gives you the formulas, a worked example, a reach curve that shows why costs rise, and clear rules for choosing the balance by objective.
Key takeaways
- Reach = unique people. Frequency = average exposures per person. Impressions = reach × average frequency.
- Reach always refers to a time window (a week, a month, a flight). Always state it.
- Average frequency hides the spread. Check the frequency distribution (1+, 3+, 5+).
- Past a point, extra budget buys repeat views, not new people. That is the reach curve.
- Default to reach for awareness and launches; add frequency for retargeting, complex messages and short deadlines.
What is the difference between reach and frequency?
Reach measures how many different people saw your ad at least once, as a number or a percentage of your target audience. Frequency measures how many times, on average, each reached person saw it. Reach tells you how wide your message spread; frequency tells you how deeply it was repeated. Together they explain every impression you bought.
| Metric | What it counts | Unit | Example |
|---|---|---|---|
| Reach | Unique people exposed at least once | People or % of target | 2,000,000 people or 40% of women 22 to 40 |
| Frequency | Average exposures per reached person | Times | 2.0 |
| Impressions | Total times the ad was served | Count | 4,000,000 |
| GRP / TRP | Reach % × frequency (gross weight) | Rating points | 40 × 2 = 80 |
| Cost per 1,000 reached | Cost ÷ reach × 1,000 | $ | $3.00 |
All definitions here match the reach entry in our media planning glossary, where you will also find related terms like GRP and effective frequency.
What is reach in advertising?
Reach in advertising is the count of unique people who saw an ad at least once during a defined period. Platforms estimate it by deduplicating impressions across devices, so one person seeing an ad on a phone and a laptop counts once. It is usually reported as a number and as a percentage of the target audience.
Three details decide whether a reach number is useful:
- The time window. Weekly reach and campaign reach are different numbers. 1 million people per week for four weeks is not 4 million campaign reach, because many are the same people.
- People versus devices. Google says its Unique Reach metrics model people across devices, formats and networks rather than counting cookies. One viewer on three devices counts once.
- Co-viewing. On connected TV, two people can watch one ad together. Google now counts co-viewers in its unique users metric, so CTV reach can exceed the number of devices.
What is frequency in advertising?
Frequency in advertising is the average number of times each reached person was exposed to an ad in a period. It is calculated as impressions divided by reach. Because it is an average, a frequency of 3 can mean everyone saw the ad three times, or some saw it once and others ten times.
That is why the frequency distribution matters more than the average. Google Ads reports frequency distribution buckets of 1+, 2+, 3+, 4+, 5+ and 10+, plus average impression frequency per user over 7 and 30 days, and recommends the 7-day and distribution metrics for judging performance.
Example: two campaigns both report an average frequency of 3.0 on 1 million people. In Campaign A, 70% of people fall between 2 and 4 exposures. In Campaign B, 50% saw the ad once and a small group saw it 15 or more times. Same average, very different results: B wasted money on a few heavy users and barely registered with half its audience.
How do you calculate reach and frequency?
Use three linked formulas. Impressions = reach × average frequency. Average frequency = impressions ÷ reach. Reach % = reach ÷ target audience size × 100. If you know any two of impressions, reach and frequency, you can find the third. GRPs are reach % multiplied by average frequency.
Formula: Impressions = Reach × Average frequency
Formula: Average frequency = Impressions ÷ Reach
Formula: Reach % = (Reach ÷ Target audience) × 100
Formula: GRP = Reach % × Average frequency
Formula: Cost per 1,000 reached = (Cost ÷ Reach) × 1,000
In planning you usually start from budget and CPM: impressions = budget ÷ CPM × 1,000. Then you choose how to split those impressions between reach and frequency. Our free reach and frequency calculator does this conversion both ways, so you can test scenarios before you open an ad platform.
Worked example: same budget, two very different plans
With $6,000 at a $1.50 CPM you buy 4,000,000 impressions. Against a 5 million audience, that can be 2 million people at frequency 2 (40% reach) or 800,000 people at frequency 5 (16% reach). Both deliver 80 GRPs, which is why GRPs alone never tell you which plan is better.
Example setup: a mid-size SUV brand targets 5,000,000 men and women aged 28 to 45 in top metros. The video budget is $6,000 and the expected CPM is $1.50.
Impressions = $6,000 ÷ $1.50 × 1,000 = 4,000,000.
| Plan A: reach-led | Plan B: frequency-led | |
|---|---|---|
| Impressions | 4,000,000 | 4,000,000 |
| Unique reach | 2,000,000 | 800,000 |
| Reach % | 40% | 16% |
| Average frequency | 2.0 | 5.0 |
| GRPs | 80 | 80 |
| Cost per 1,000 reached | $3.00 | $7.50 |
| Best for | Launch, awareness, broad category | Retargeting, complex message, short sale window |
For a new model launch, Plan A wins: 1.2 million more people now know the car exists. For a 10-day year-end offer aimed at people who already visited the configurator, Plan B is the smarter buy, because those people need reminders, not introductions.
Why does frequency rise when you try to buy more reach?
Because audiences are not equally easy to reach. The first dollars reach heavy platform users cheaply. As budget grows, the platform keeps serving those same people while hunting for light users, so average frequency climbs and each extra person costs more. Plotting reach against budget gives a curve that flattens, called the reach curve.
Example reach curve for the same 5 million audience at a $1.50 CPM (illustrative numbers, not a benchmark):
| Budget | Impressions | Reach % | Reach (people) | Avg frequency | Cost per extra person reached |
|---|---|---|---|---|---|
| $1,200 | 800,000 | 12% | 600,000 | 1.3 | $0.002 |
| $2,400 | 1,600,000 | 20% | 1,000,000 | 1.6 | $0.003 |
| $4,800 | 3,200,000 | 30% | 1,500,000 | 2.1 | $0.0048 |
| $9,600 | 6,400,000 | 38% | 1,900,000 | 3.4 | $0.012 |
| $19,200 | 12,800,000 | 44% | 2,200,000 | 5.8 | $0.032 |
Doubling budget from $9,600 to $19,200 adds only 300,000 new people, at $0.032 each, about 16 times the cost of the first people reached. Most of the extra money becomes frequency. When you see this pattern, the fix is usually to add a new channel or audience that reaches different people, not to push more money into the same one.
Should you prioritise reach or frequency?
Prioritise reach when people do not yet know you, when the product is bought by many people occasionally, or when you are maintaining a big brand. Prioritise frequency when the message is complex, the audience is small and warm, or there is a hard deadline. Most plans need reach first, then enough frequency to be remembered.
| Situation | Lean toward | Starting point to test |
|---|---|---|
| New brand or product launch | Reach, then build frequency | Max reach at 1 to 3 per week |
| Established brand, always-on | Reach every week (recency) | Steady weekly reach, low frequency |
| Short sale or event deadline | Frequency | 3 to 5 exposures inside the window |
| Retargeting warm audiences | Frequency with a cap | Cap to avoid fatigue, rotate creative |
| Complex or high-price product (cars, B2B software) | Balanced | Reach plus sequenced messages |
| Small budget | Reach in one channel | Narrow audience, not thin spend |
The weekly reach idea comes from recency planning. Erwin Ephron argued in the Journal of Advertising Research (1997) that most advertising works by reaching people who are ready to buy, so reaching more people each week beats hitting the same people repeatedly.
Platform data points the same way. In a 2021 Nielsen marketing mix meta-analysis commissioned by Google and cited on the Google Ads blog, TV advertisers saw 41% lower ROI when weekly frequency was 6 or more, while YouTube brands could raise average weekly frequency from one to three with consistent ROI. Treat vendor-commissioned research as a signal, not proof, and test in your own account.
How do you control reach and frequency on Google and Meta?
Use frequency caps to set a maximum, and frequency goals to aim for an average. On YouTube, Target Frequency campaigns optimise toward a weekly or monthly frequency goal while maximising unique reach. On Meta, the reservation buying type lets you plan reach and frequency in advance, while auction campaigns use caps on reach-objective campaigns.
- YouTube: Google’s Target Frequency supports weekly goals of 2 to 7 for multi-format ads and 2 to 4 for in-stream only, or monthly goals of 4 to 12 and 4 to 8 respectively, according to Google Ads Help on Target Frequency.
- Google Reach Planner: forecasts on-target reach and frequency for YouTube plans before you buy.
- Meta: the reservation buying type, formerly called reach and frequency, gives predictable reach at a fixed CPM with a frequency cap or target frequency. Auction campaigns with a reach objective also let you set a cap.
What mistakes do people make with reach and frequency?
The biggest mistakes are adding reach across channels as if audiences never overlap, comparing numbers from different time windows, reading average frequency without the distribution, treating impressions as people, and pushing more budget into a saturated audience. Each one makes a plan look bigger or cheaper than it really is.
- Adding reach across platforms. 2 million on YouTube plus 1.5 million on Meta is not 3.5 million. Use deduplicated tools or estimate combined reach as A + B − (A × B) in percentages.
- Mixing windows. Compare weekly with weekly and flight with flight.
- Ignoring the tail. A 3.0 average with a large 10+ bucket means wasted impressions.
- Calling impressions reach. Impressions are always equal to or bigger than reach.
- Buying the flat part of the curve. If extra spend adds frequency but not reach, add a new audience or channel.
What this means for marketers and creators
For marketers and media planners
- Write reach targets as “X% of audience at Y+ frequency per week” in every plan, as shown in our guide on how to create a media plan.
- Report cost per 1,000 reached next to CPM. A cheap CPM with low reach is often an expensive plan.
- When reach stalls and frequency climbs, move budget to a channel that reaches different people.
For creators and small teams
- On your own analytics, “accounts reached” is reach and “views” is closer to impressions. Views divided by accounts reached is your frequency.
- If most views come from the same followers, your content is building frequency, not reach. Collaborations and Shorts or Reels that reach non-followers grow reach.
- For paid boosts, pick the reach objective for new audiences and cap how often the same person sees it.
Frequently asked questions
Is reach or frequency more important?
Neither is always more important. Reach matters most for launches, awareness and brands bought by many people. Frequency matters more for retargeting, complex messages and short deadlines. Most plans should secure reach first, then add enough frequency for people to remember the ad, while capping it so budget is not wasted.
What is the difference between reach and impressions?
Reach counts unique people who saw an ad at least once. Impressions count every time the ad was served, including repeats to the same person. If 100,000 people each saw an ad three times, reach is 100,000 and impressions are 300,000. Impressions divided by reach gives average frequency.
How do you calculate ad frequency?
Divide total impressions by unique reach for the same time period. Example: 1,200,000 impressions reaching 400,000 people gives an average frequency of 3.0. Check the frequency distribution as well, because an average can hide people who saw the ad once and others who saw it far too often.
What is a good frequency for digital ads?
There is no universal number. A common starting point for awareness video is 1 to 3 exposures per person per week, adjusted by results. Warm retargeting audiences can take more. Watch for rising frequency with falling click-through rate or flat reach, which signals fatigue or a saturated audience.
Can reach be higher than impressions?
No. Every person reached needs at least one impression, so reach can equal impressions at most, which would mean a frequency of exactly 1.0. On connected TV, co-viewing models can count more than one person per impression, so check how your platform defines people before comparing.
How are GRPs related to reach and frequency?
Gross rating points equal reach as a percentage of the target audience multiplied by average frequency. Reaching 40% of your audience at a frequency of 2 gives 80 GRPs, and so does reaching 16% at a frequency of 5. GRPs measure total weight, not how that weight is spread.
Next steps
Plug your budget, CPM and audience size into our reach and frequency calculator to see how many people you can reach and how often. If you are building your first plan, the Media Planning Playbook covers the basics, and the glossary explains GRPs and related terms. Join the free TechMachaw newsletter for one practical media planning guide every week.
