Radius Map Use Cases

Manhattan is a narrow island bounded by the Hudson River on the west and the East River on the east, so a radius drawn from midtown crosses water in several directions and reaches different neighborhoods depending on which way it points.

A 10-mile radius from downtown Los Angeles reaches Hollywood (~6 miles northwest) and Glendale (~6 miles north), but Santa Monica (~14 miles west) and Long Beach (~20 miles south) fall outside.

Chicago is laid out on a numbered street grid centered at State and Madison, with addresses counting up by 100 per block from that zero point. That regular layout makes it easy to sketch a service area outward from downtown in each direction without a tape measure.

A 10 km radius from Charing Cross reaches the inner boroughs out to Hampstead Heath (~6 km northwest) and Greenwich (~9 km east), while Wimbledon (~11 km southwest) and Croydon (~14 km south) sit just outside it. Push the radius out to 25 km and it reaches Heathrow (~23 km west), Romford (~23 km east), and Watford (~25 km northwest).

From the Manchester city centre, a 25 km radius reaches well beyond the inner boroughs — a useful starting point for catchment planning across the wider conurbation.

The City of Paris (intramuros) is bounded by the Boulevard Périphérique, a near-circular ring road. A 5 km radius from the centre fits the entire 20 arrondissements inside the Périphérique.

The S-Bahn Ringbahn (S41/S42) is a circular railway that loops around inner Berlin — a handy proxy for "central Berlin" when you draw a radius. From central Berlin (Mitte), Charlottenburg sits about 8 km west and Köpenick about 14 km southeast.

Madrid is encircled by orbital motorways — the inner M-30, the M-40, the partial M-45 on the eastern side, and the outer M-50. Each ring roughly corresponds to a shift in urban character, so they make natural reference points when you draw a radius around the centre.

Rome is encircled by the Grande Raccordo Anulare (GRA), an orbital motorway that rings the city and separates dense urban Rome from its outer suburbs. A radius drawn from the historical core is a handy way to approximate "inside the ring" without tracing the road by hand.

The Yamanote Line forms a rail loop around central Tokyo. A 5 km radius from Shinjuku Station reaches Shibuya (~3 km south) and Tokyo Tower (~5 km southeast), covering much of the dense core that loop encloses.

Sydney wraps around its harbour, and a radius drawn from the CBD is shaped by water on three sides. A 1 km radius from Martin Place barely leaves the historic core, while a 25 km radius reaches out to Parramatta (~4 km northwest), Hornsby (~21 km northwest), and Cronulla (~22 km south).

A 15 km radius from Nathan Phillips Square reaches the inner Greater Toronto Area but stops short of Mississauga (~23 km west) and Vaughan (~22 km northwest). Because Lake Ontario sits directly south, the southern arc of any Toronto radius falls over water.

San Francisco proper sits at the tip of a peninsula, with San Francisco Bay to the east and the Pacific Ocean to the west, so a radius drawn from Union Square runs out over water in several directions before it covers much land.

A radius drawn from Boston Common reaches far beyond the city limits fast — a 10-mile radius already pulls in Newton (~7 miles west), Quincy (~8 miles southeast), and Lexington (~10 miles northwest).

Seattle sits between Puget Sound to the west and Lake Washington to the east, so a radius drawn from Pike Place reaches water in both directions before it reaches many of the suburbs.

Miami sits between the Atlantic Ocean to the east and the Everglades to the west, so a circle drawn around the city tends to capture a lot of water and protected wetland alongside the urbanized area.

The District of Columbia is a small federal district, and the I-495 Capital Beltway rings the inner core around it. On a radius map centered on the White House, the first resolvable suburbs appear around 6 miles out: Alexandria (~6 miles south) and Silver Spring (~6 miles north).

Vancouver sits between the North Shore Mountains, the Strait of Georgia, and the Fraser River delta, so a radius drawn from the downtown waterfront quickly runs into water or mountains. Richmond lies about 13 km south, Vancouver International Airport about 12 km southwest, and Surrey about 22 km southeast.

Working outward from O'Connell Bridge, a 25 km radius reaches suburbs and commuter towns such as Swords (~13 km north), Bray (~19 km southeast), and Maynooth (~23 km west). The M50 ring road wraps around the city, and its loop is often used as shorthand for the edge of Dublin proper.

Amsterdam is unusually compact — a 2 km radius from Dam Square already covers the historic canal ring (Grachtengordel) and the medieval centre, and a 10 km radius reaches across the city to Amsterdam Zuidoost (~9 km southeast) and Zaandam (~8 km northwest).

Barcelona sits between the Mediterranean Sea and the Collserola hills. A radius drawn from Plaça de Catalunya runs into sea or mountain going seaward or inland, while reaching much further along the coast — northeast toward Badalona (~9 km northeast) and southwest toward L'Hospitalet de Llobregat (~5 km southwest).

Munich grew outward from Marienplatz in a series of loops — the medieval old-town wall, the S-Bahn ring, and the Mittlerer Ring road — which makes radius-based catchments easy to picture from the centre.

Singapore is a compact island city-state. From the centre near Marina Bay, Tuas on the far western tip is only about 22 km away and Woodlands by the Causeway about 18 km northwest, so a single 25 km radius reaches every named district at once — Tanjong Pagar, Bedok, Tampines, Jurong East, Changi Airport, Woodlands and Tuas.

Hong Kong is split across Hong Kong Island, Kowloon, and the New Territories. Measured straight-line from Statue Square in Central, a 10 km radius reaches Tsim Sha Tsui, Mong Kok, Kowloon Tong, and east to Tseung Kwan O, while Hong Kong International Airport lies about 24 km west and the far New Territories towns such as Tuen Mun (~23 km northwest) sit near the edge of a 25 km radius.

A 5 km radius drawn from the Sky Tower reaches the central city, the inner suburbs, and Devonport (~3 km northeast) across the Waitematā Harbour. The Waitematā Harbour lies to the east and the Manukau Harbour to the west.

Houston is one of the most sprawling major US cities, built on flat terrain with few natural radius barriers aside from the Houston Ship Channel to the east. A 15-mile radius from Downtown Houston (City Hall) reaches close-in communities like Bellaire, Meyerland, Galena Park, and Pasadena, while second-ring commuter towns such as Kingwood, La Porte, and Baytown sit beyond it.

Phoenix is the 5th-largest city in the US with a 2020 Census population of 1,608,139 in the city proper, spread across the flat Valley of the Sun.

Philadelphia is a dense, river-bounded city of 1,603,797 people (2020 Census), with the Schuylkill River running through downtown and the Delaware River forming the eastern border with New Jersey.

A 12-mile radius from Main Plaza (San Fernando Cathedral) reaches the inner suburbs including Alamo Heights (~4 miles northeast) and Castle Hills (~7 miles north), while nearby Hill Country gateways like Boerne (~29 miles northwest) sit well outside it.

San Diego's geography is fragmented by canyons and constrained by water — the Pacific Ocean blocks the west, and San Diego Bay splinters downtown from Coronado and the South Bay. A 10-mile radius from Downtown San Diego (Civic Center) reaches diverse neighborhoods, from Coronado and the beach side across the bay to inland suburbs like Spring Valley, but geography means you often have to drive around obstacles that don't appear on a straight-line map. Coronado sits ~2 miles southwest, while inland El Cajon is ~13 miles northeast.

A 12-mile radius from downtown Dallas reaches the nearest ring of towns, with Irving about 9 miles west, Duncanville about 11 miles southwest, and Grand Prairie about 12 miles west all falling inside it. Fort Worth sits roughly 31 miles west and Plano about 18 miles north, so understanding straight-line distance helps when a service boundary needs to cross between Dallas, Tarrant, and Collin counties, each of which has its own tax, licensing, and regulatory rules.

Austin sits along the Colorado River, which runs through downtown as Lady Bird Lake. A 10-mile radius from downtown Austin (Congress Avenue) reaches west toward the Hill Country, spreads east across the inner city, and reaches West Lake Hills (~4 miles northwest), but it stops short of the first ring of suburbs: Round Rock sits ~17 miles north and Cedar Park ~17 miles north of downtown.

Denver sits on the High Plains at 5,280 feet elevation (the "Mile High City"), where the flat grid of the urban core runs up against the Rocky Mountain foothills to the west near Golden (~12 miles west). The grid layout and flat terrain keep straight-line radius calculations close to on-road distance in most directions until you reach the foothills; terrain and the major north-south corridors (I-25, I-270) become the real distance measure for most residents.

Atlanta's city proper is home to 498,715 people (2020 Census), while the surrounding metro area stretches far beyond — so a 12-mile radius from downtown reaches out to Buckhead, Sandy Springs, and Smyrna while still stopping short of outer suburbs like Marietta, Kennesaw, and Alpharetta.

Portland, Oregon's 2020 census population of 652,503 makes it the Pacific Northwest's largest city, set along the Willamette River where the water splits the city into distinct east and west districts.