A designated market area (DMA) is a group of U.S. counties that Nielsen assigns to a single local television market, based on where viewers spend the most time with home-market stations. Nielsen defines 210 DMAs for the 2025-26 season, ranks them by TV households, and uses them to measure local ratings and to price local advertising.
Originally published May 28, 2021. Rewritten and fact-checked October 14, 2026.
What is a designated market area?
A designated market area is Nielsen's name for a local television market, and the same area is also called a media market, broadcast market or TV market. PPC Land notes that Nielsen owns the boundaries outright, so the term always means a Nielsen-defined region.
Marketers sometimes extend the term to online and newspaper audiences, because the same geographic boundaries are used to plan and report other local media. Market researchers use DMAs to see audience demographics and what each audience watches and listens to, including new shows and radio programs.
How do designated market areas work?
Designated market areas divide the United States into 210 regions so that local ratings, programming and ad prices can be compared market by market.
How does Nielsen assign a county to a DMA?
Nielsen assigns each county to the DMA whose home-market stations capture the dominant share of viewing there, and each county belongs to exactly one of the 210 DMAs, according to GrowthFactor. Markets are named for their largest city but often include surrounding metro areas, as in Washington, D.C. (Hagerstown), which ranks eighth for 2025-26 in the Nielsen rankings listed on Wikipedia.
Illustrative scenario: if most viewers in a county watch Baltimore-based television stations, that county sits in the Baltimore DMA even when it is close to the Washington, D.C. market. Viewing habits, not distance, decide the assignment.
How are DMAs ranked?
Nielsen ranks DMAs by the number of TV households inside them and updates the rankings each September at the start of the broadcast season, according to Methodshop. TV homes for 2025-26 stand at 128 million, up 2 percent from 125.8 million in 2024-25.
| Rank, 2025-26 | Designated market area |
|---|
| 1 | New York |
| 2 | Los Angeles |
| 3 | Chicago |
| 4 | Dallas-Fort Worth |
| 5 | Philadelphia |
| 6 | Houston |
| 7 | Atlanta |
| 8 | Washington, D.C. (Hagerstown) |
| 9 | San Francisco-Oakland-San Jose |
| 10 | Boston (Manchester) |
| 210 | Glendive, Montana |
GrowthFactor, citing Nielsen's 2024-25 market estimates, puts New York at about 7.49 million TV homes and Los Angeles at about 5.84 million.
Why do DMAs set advertising costs?
DMA rank drives local ad pricing because a larger market reaches more homes, so a spot in New York costs far more than one in a small market such as Montgomery, Alabama, per GrowthFactor. Nielsen ratings also show media owners how programs perform in each market, so stations schedule programs accordingly and advertisers buy the best-performing slots for their target audiences.
What is the difference between a DMA and an ADI?
An ADI, or Area of Dominant Influence, was the older market definition from the ratings firm Arbitron, and the DMA is Nielsen's version. PPC Land reports that under federal rule 47 CFR 76.55(e), ADIs governed until January 1, 2000, after which a commercial station's market is its Nielsen DMA.
What are the best practices for DMA targeting?
Four practices help PR and marketing teams use DMAs well, and the guidance below is EPR's editorial judgment, not a Nielsen standard.
Use DMA data to match message to market
DMA data supplies the demographic categories that public relations and marketing teams need to tailor ads and products. Timing matters as much as geography, so the right program and time slot decide how much of the target audience a message reaches.
Tailor pitches to the market
Pitches in large DMAs face more competition for coverage, so a story should be built around what that market's audience needs. Outlets in large markets tend to be selective about the stories they accept, which makes a local angle more useful than a national one.
Match the budget to the market
Costs vary widely by DMA, so teams should set budgets against the specific markets they target. Firms with smaller budgets often get more from smaller DMAs, where a limited spend can still reach a meaningful share of households.
Use specialists for market selection
Choosing a DMA for a message depends on several factors, and a small error can be costly. Firms that specialize in connecting marketers with the right media market can reduce that risk.
How has the internet changed DMAs?
The internet, cable and social media let people reach content from outside their own DMA, which makes geographic targeting less exact than it once was. PR and marketing agencies should adapt their targeting strategies so purchased airtime still reaches the intended audience.
Nielsen's own measurement has changed too: GrowthFactor reports that since January 2025 the local-market ratings currency blends Nielsen's panel with set-top-box and smart-TV data, replacing the older panel-and-diary method. PPC Land also reports that Meta removed Nielsen DMAs from targeting and reporting in automotive model ads on June 22, 2026, and that programmatic bid requests do not carry a Nielsen DMA. Both reports come from a single source, so treat them as indicators, not settled facts.
