Channel Islands
Crown Dependencies archipelago comprising the Bailiwicks of Jersey and Guernsey
The Channel Islands form an archipelago in the English Channel off the Normandy coast. Consisting of Jersey, Guernsey, Alderney, Sark, Herm, and smaller islets, they operate under dedicated postal administrations (Guernsey Post and Jersey Post) fully integrated with the UK postal system under outcodes GY and JE.
Channel Islands Area Statistics & Quick Facts
Key geographic measurements, boundaries, and postal metrics.
38.50 mi
Span across longitude
30.80 mi
Span across latitude
76.45 mi²
198.01 km² · 19,801 ha
42.20 mi
Longest diagonal span
145.50 mi
Total coastal perimeter
15
Unique outcodes
35
Postal distribution sectors
5
Official postal jurisdictions
6,450
Unit postcodes mapped
176,500
~0.26% of British Isles
The Channel Islands region has an estimated population of 176,500 and covers 19,801 hectares (76.45 mi²). Roughly 0.26% of the British Isles population lives here across 15 postcode districts.
How built up is the Channel Islands area?
Compares building footprint coverage against total land area across each postcode district in the Channel Islands.
Density Highlights
Least urban district is GY10 (Sark) at 0.95% · Most urban is JE1 (St Helier) at 18.64%
The least built-up district is GY10 (Sark at 0.95%) and the most built-up is JE1 (St Helier at 18.64%). Urban infrastructure is heavily focused in the island capitals of St Helier and St Peter Port, surrounded by protected coastal headlands and agricultural parishes.
| Postcode district | Settlement / Parish | Total area (m²) | Footprint area (m²) | Built percentage |
|---|---|---|---|---|
| GY10 | Sark Sark | 5,450,000 | 51,775 | 0.95% |
| GY8 | Torteval & Forest Guernsey | 7,420,000 | 89,040 | 1.20% |
| GY7 | St Pierre du Bois Guernsey | 6,250,000 | 87,500 | 1.40% |
| GY9 | Alderney Alderney | 7,800,000 | 140,400 | 1.80% |
| GY5 | St Saviour (Guernsey) Guernsey | 6,370,000 | 121,030 | 1.90% |
| GY6 | St Andrew Guernsey | 4,490,000 | 98,780 | 2.20% |
| JE3 | Western & Northern Jersey Jersey | 74,800,000 | 2,019,600 | 2.70% |
| GY4 | St Martin (Guernsey) Guernsey | 7,340,000 | 242,220 | 3.30% |
| GY3 | Castel Guernsey | 10,200,000 | 367,200 | 3.60% |
| JE2 | St Saviour, St Clement & Grouville Jersey | 32,800,000 | 1,836,800 | 5.60% |
| GY2 | St Sampson & Vale Guernsey | 14,830,000 | 1,067,760 | 7.20% |
| GY1 | St Peter Port & Herm Guernsey | 8,660,000 | 1,082,500 | 12.50% |
| JE1 | St Helier Jersey | 10,600,000 | 1,975,840 | 18.64% |
| Total | Regional Average | 198,010,000 | 9,180,445 | 4.64% |
Towns & Parishes in Channel Islands
Explore primary settlements, parishes, and coastal communities across the region.
St Helier
JE1 / JE2The vibrant capital and commercial heart of Jersey, hosting the international financial district, harbour terminals, central shopping precincts, and cultural institutions.
St Peter Port
GY1The picturesque capital of Guernsey characterised by historic cobbled streets, sea-facing terraces, Castle Cornet, and major financial service hubs.
St Anne
GY9The historic main settlement of Alderney with Georgian architecture, cobblestone high streets, St Anne's Church, and peaceful island amenities.
St Sampson
GY2Guernsey's second town situated along the northeastern coast, anchored around the historic commercial harbour and "The Bridge" shopping district.
St Brelade & St Aubin
JE3A premier coastal destination featuring picturesque St Aubin's Harbour, golden sandy beaches at St Brelade's Bay, and Les Quennevais commercial centre.
St Saviour
JE2An eastern parish adjoining St Helier, hosting government headquarters, major secondary and higher educational campuses, and residential neighbourhoods.
Castel (Sainte-Marie-du-Câtel)
GY3The largest parish by area in Guernsey, spanning the western Atlantic coastline from Cobo Bay to Vazon Bay, famous for sunsets and surfing.
Vale
GY2 / GY3Northern parish encompassing L'Ancresse Common, 18-hole links golf courses, historic coastal watchtowers, and Bordeaux Harbour.
St Clement
JE2A compact southeastern coastal parish renowned for its expansive intertidal zone ("moonscape"), Pontac slipway, and proximity to St Helier.
Gorey & St Martin
JE3Iconic eastern fishing village beneath Mont Orgueil Castle, lined with seafood restaurants, pier moorings, and Royal Bay of Grouville vistas.
St Peter
JE3Central-western parish hosting Jersey Airport, classic granite farmsteads, community village greens, and traditional cider orchards.
St Ouen
JE3Expansive western parish with the 3-mile sweep of St Ouen's Bay, Les Mielles nature reserve, prehistoric dolmens, and historic manor houses.
St Martin (Guernsey)
GY4Southeastern parish featuring Sausmarez Manor, subtropical gardens, and dramatic cliff walks above Fermain Bay and Saints Bay.
Sark (The Avenue)
GY10A unique, motor-vehicle-free Dark Sky Island community linked by unpaved tracks, tractor transport, horse carriages, and dramatic sea arches.
Herm Island (Harbour Village)
GY1An unspoilt, tranquil island featuring white-sand Shell Beach, Belvoir Bay, coastal puffin colonies, and a welcoming harbour village.
St Lawrence
JE3Central parish known for lush Waterworks Valley, historic Jersey War Tunnels, and peaceful rural footpaths.
Grouville
JE2Eastern parish encompassing the Royal Jersey Golf Club, Gorey Village outskirts, and the fertile agricultural Fief of Grouville.
Trinity
JE3Northern coastal parish home to Jersey Zoo (Durrell Wildlife Conservation Trust), Bouley Bay hill climb, and rugged cliffs.
St Saviour (Guernsey)
GY5Peaceful western parish containing St Saviour's Reservoir Millennium Walk and scenic rolling Guernsey countryside.
Forest
GY8Southern upland parish hosting Guernsey Airport, Petit Bôt Bay valley, and cliff walks overlooking the Channel.
Postcode Areas (Outcodes) in Channel Islands
Browse area-level reports and street indexes for each postcode sector.
St Helier (Central & Commercial)
St Saviour, St Clement, Grouville
St Brelade, St Peter, St Ouen, Rural Parishes
Jersey PO Boxes & Business Non-geographic
St Peter Port & Herm Island
St Sampson & Vale (South)
Castel & Vale (North)
St Martin
St Saviour
St Andrew
St Pierre du Bois
Torteval & Forest
Alderney Island
Sark Island
Locality Research & Area Context: Channel Islands
Education & Catchments
Educational structures in Channel Islands reflect distinctive local governance. View individual area reports to analyze school capacity, inspection outcomes, and nearby college or higher education hubs.
Digital Infrastructure & 5G
Fiber broadband networks and 5G mobile deployments are expanding across coastal and island districts. Use our connectivity mapping to check Gigabit readiness and mobile reception benchmarks.
Safety & Community Metrics
Postcodewise compiles official policing and local safety datasets across all residential sectors to provide transparent, street-level safety scores and trend evaluations.