2,512 km²
Total area
IGN/INSEE data. The perimeter covers the 24 municipalities, excluding the exclusive economic zone.
Practical FAQ · Geographic data
How Big Is Reunion Island? 2,512 km², Dimensions and Comparisons
How big is Reunion Island in square kilometres, what are its exact dimensions, how does it compare with Corsica, Martinique or the Paris region, and where does everyone live? Here's all the island's geographic data, laid out simply.
2,512 km² in area70 × 50 km across3,070m at Piton des Neiges870,000 residents
Updated in October 2026
The essentials before you go
Reunion Island looks small on a world map, but it packs in a diversity of landscapes comparable to a small continent: lagoon, savanna, primary forest, U-shaped cirques (vast natural amphitheatres), an active volcano, a summit at 3,070m. To plan a trip that covers that variety, see my complete guide to planning your trip and the 10-day itinerary.
You're on Sous Les Étoiles 974
The independent guide to planning your trip to Reunion Island
I bring together more than 470 partner activities (helicopter, paragliding, hiking, whale-watching cruises, airport transfers...), a wide catalogue of hotels and gîtes to cover the island's 2,512 km², and dozens of practical guides. An independent site run by someone passionate about Reunion Island.
Reunion Island's official area stands at 2,512 km², according to INSEE and IGN data. The island forms an elongated ellipse oriented north-west/south-east, 70km along its long axis and 50km wide at its maximum. The coastline runs 207km and can be driven in a single day via the RN1 national road (west and south) and the RN2 (east and north).
This modest area is dominated by two volcanic massifs: Piton des Neiges in the north-west, a dormant volcano reaching 3,070m, and Piton de la Fournaise in the south-east, an active volcano at 2,632m. Together, they cover more than three-quarters of the island. The population therefore lives mainly on the narrow coastal strips and in the high-altitude central plains.
Average density works out at 346 residents/km² for 870,000 residents, about twice the mainland French average. But that figure masks a huge gap: central Saint-Denis exceeds 4,000 residents/km², while the Mafate cirque, accessible only on foot or by helicopter, has fewer than 5 residents/km².
The rest of this page details the key figures, a comparison with other islands and regions, the breakdown of the terrain, the main municipalitiesand the island's administrative status within the French Republic.
Key figures
Reunion Island in six geographic figures
Area, dimensions, coastline, peak, municipalities and population. Six reference points to grasp the island's proportions at a glance.
70 × 50 km
Island dimensions
North-west/south-east axis: 70km. Maximum width: 50km. A roughly oval shape.
207 km
Coastline length
A full loop of the island via the RN1 and RN2 national roads, along the entire coastal perimeter.
3,070m
Highest point
The summit of Piton des Neiges, the highest peak in the Indian Ocean and the highest point of any French overseas department.
24 municipalities
Administrative divisions
Grouped into 5 inter-municipal bodies (TCO, CINOR, CIVIS, CASUD, CIREST) and 5 sub-regions.
870,000 residents
Population
2024 INSEE estimate. Average density of 346 residents/km², comparable to Brittany.
Concentrated terrain
3,070m altitude just 25km from the sea
Comparisons
Reunion Island against other islands and regions
To put the island's size in perspective, here's its area ratio against ten reference points: other French overseas departments, an Indian Ocean neighbour, mainland regions.
Reunion Island
reference- Area
- 2,512 km²
A tropical island in the south-west Indian Ocean
Luxembourg
× 1.03- Area
- 2,586 km²
The most comparable country in size
Mauritius
× 0.81- Area
- 2,040 km²
A neighbour 170km to the north-east, 23% smaller
Martinique
× 0.45- Area
- 1,128 km²
A Caribbean French department, half the size
Guadeloupe
× 0.65- Area
- 1,628 km²
A Caribbean archipelago larger than Martinique
Mayotte
× 0.15- Area
- 374 km²
The smallest French overseas department, 7 times smaller than Reunion Island
Corsica
× 3.45- Area
- 8,681 km²
A Mediterranean island, almost 3.5 times the size of Reunion Island
Paris region (Île-de-France)
× 4.78- Area
- 12,011 km²
Mainland France's densest region
Mainland France
× 217- Area
- 543,940 km²
217 times larger; Reunion Island represents 0.46% of that area
French Guiana
× 33- Area
- 83,534 km²
The largest French overseas department, about 33 times the size of Reunion Island
| Territory | Area | Ratio vs Reunion Island | Note |
|---|---|---|---|
| Reunion Island | 2,512 km² | reference | A tropical island in the south-west Indian Ocean |
| Luxembourg | 2,586 km² | × 1.03 | The most comparable country in size |
| Mauritius | 2,040 km² | × 0.81 | A neighbour 170km to the north-east, 23% smaller |
| Martinique | 1,128 km² | × 0.45 | A Caribbean French department, half the size |
| Guadeloupe | 1,628 km² | × 0.65 | A Caribbean archipelago larger than Martinique |
| Mayotte | 374 km² | × 0.15 | The smallest French overseas department, 7 times smaller than Reunion Island |
| Corsica | 8,681 km² | × 3.45 | A Mediterranean island, almost 3.5 times the size of Reunion Island |
| Paris region (Île-de-France) | 12,011 km² | × 4.78 | Mainland France's densest region |
| Mainland France | 543,940 km² | × 217 | 217 times larger; Reunion Island represents 0.46% of that area |
| French Guiana | 83,534 km² | × 33 | The largest French overseas department, about 33 times the size of Reunion Island |
2024 INSEE data for French regions and overseas departments. For Mauritius and Luxembourg, sources are Statistics Mauritius and STATEC.
Terrain breakdown
Four major geographic areas
Across 2,512 km², the island breaks down into two imposing volcanic massifs, high-altitude central plains and inhabited coastal strips.
The Piton des Neiges massif
≈ 1,100 km² · 44% of the island
A dormant volcano forming the north-west of the island. It includes the three cirques (Cilaos, Mafate, Salazie), carved out by erosion over two million years. The summit reaches 3,070m. The drop to the sea happens over just 25km as the crow flies, an average gradient of more than 12%.
The Piton de la Fournaise massif
≈ 830 km² · 33% of the island
An active volcano occupying the south-east. Its summit stands at 2,632m, a dome built up by 250 recorded historical eruptions since 1640. The Enclos Fouqué descends towards the ocean as far as Pointe du Tremblet, where each major eruption occasionally extends the shoreline by a few hectares.
The central plains
≈ 280 km² · 11% of the island
Plaine des Cafres and Plaine des Palmistes, between 1,200 and 1,600m altitude. They link the two massifs and are around ten kilometres wide. Expect a temperate climate, cattle farming, market gardening and the stopover town of Bourg-Murat on the road to the volcano.
The coastal plains
≈ 300 km² · 12% of the island
Narrow coastal strips where most of the population lives. The widest plain (Saint-Denis to Saint-André, an average of 18km by 4km) is home to a third of all Reunion Islanders on its own. The west coast has only a thin habitable strip between the ocean and the first foothills.
Active volcano
Piton de la Fournaise covers a third of the territory
Municipalities and population
The six municipalities home to half of Reunion Islanders
The island has 24 municipalities in total. Here are the six most populous, home to nearly 530,000 of the island's 870,000 residents on their own.
Saint-Denis
NorthResidents
≈ 150,000Area
143 km²The region and department's administrative capital, home to the prefecture, the university and the main hospital. Density exceeds 1,000 residents/km² in the colonial-era town centre. The municipality stretches from the sea to the Roche Écrite massif at 2,277m.
Saint-Paul
WestResidents
≈ 106,000Area
241 km²The first town founded by the French, in the 17th century, and the second most populous municipality. It covers a coastal strip running from La Possession to south of La Saline, and climbs up to the Maïdo at 2,200m altitude.
Saint-Pierre
SouthResidents
≈ 87,000Area
96 km²The economic capital of the south and the third most populous municipality. It has a commercial port, a university and a regional hospital, plus a lively seafront, the Ravine Blanche district, and a Sunday market recognised as the island's largest.
Le Tampon
SouthResidents
≈ 80,000Area
165 km²A municipality in the Hauts (highlands) that climbs from the coast up to Plaine des Cafres at 1,600m, with an agricultural market and a cooler climate than the coast. Known for its gardens, its fruit growing and its social sciences university campus.
Saint-André
EastResidents
≈ 56,000Area
53 km²The island's Tamil heart, with Thursday and Saturday markets, colourful temples, sugar-cane plains and a strong tradition of cane and vanilla growing. One of the densest municipalities (more than 1,000 residents/km²).
Saint-Louis
SouthResidents
≈ 53,000Area
99 km²The gateway to Cilaos via the famous road with 420 hairpin bends. It has the historic Gol sugar refinery (still operating), a 19th-century mosque and the Cascade des Aigrettes waterfall. A mixed population of Creole, Indian and African descent.
For more on the island's towns, see my guides to Saint-Denis, Saint-Pierre, Saint-Leu or the Explore Reunion Island by location page.
Administrative status
An overseas department, a region, and a European territory
Institutionally, Reunion Island is simultaneously a department, a region and an outermost territory of the European Union.
Overseas department
Reunion Island became a French department on 19 March 1946, through the departmentalisation law, at the same time as Martinique, Guadeloupe and French Guiana. It's designated by postcode 974, which is also its INSEE code.
Single-department region
Since 1982, Reunion Island has also been a French region. Like Martinique, Guadeloupe and French Guiana, it's described as a single-department region: the regional council and the departmental council coexist over the same territory.
EU outermost region
Reunion Island is one of the nine outermost regions (OMRs) of the European Union. As such, the island receives ERDF, ESF and EAFRD structural funds, and the euro is legal tender there, as across the rest of the eurozone.
A note on terminology
A quick clarification: Reunion Island is a French overseas department and region (DROM in French), not an overseas territory (the old TOM status). TOM status disappeared with the 2003 constitutional revision, replaced by overseas collectivities (COM: French Polynesia, Saint-Barthélemy, Saint-Martin, Saint-Pierre-et-Miquelon, Wallis-et-Futuna) and special statuses (New Caledonia, the French Southern and Antarctic Lands). For the full picture, see my page on Reunion Island: department or overseas territory?
Three cirques
Cilaos, Mafate, Salazie: the interior sculpted by erosion
Official sources
Where to check the geographic data
Three references used by public authorities and research institutes for official figures on area, population and terrain.
Frequently asked questions
Reunion Island's size, in practice
What is the size of Reunion Island?
Reunion Island covers 2,512 km² according to official IGN and INSEE data. The island measures around 70km from north-west to south-east, and 50km at its widest point. The coastline runs 207km, covered by the RN1 national road on the west and the RN2 on the east.
How many people live in Reunion Island?
Around 870,000 residents, according to the 2024 INSEE estimate, an average density of 346 residents/km². The population is concentrated on the coastal plains, and the northern sub-region alone (Saint-Denis to Saint-André) is home to more than a third of all Reunion Islanders. The Hauts (highlands) account for less than 5% of the population.
Is Reunion Island bigger than Corsica?
No, Corsica is 3.45 times larger, at 8,681 km² versus 2,512 km² for Reunion Island. By comparison, Reunion Island is 2.2 times larger than Martinique (1,128 km²) and nearly 7 times larger than Mayotte (374 km²). The most comparable country in mainland Europe is Luxembourg, at 2,586 km².
What is the highest point in Reunion Island?
Piton des Neiges, a dormant volcano that reaches 3,070m altitude. It's the highest peak in the Indian Ocean and the highest point of any French overseas department. The hike to its summit takes 2 days with an overnight stay in a mountain lodge at Piton des Neiges. Piton de la Fournaise, the second-highest peak, reaches 2,632m.
How many municipalities does Reunion Island have?
The island has 24 municipalities, grouped into 5 inter-municipal bodies: TCO (west), CINOR (north), CIVIS (south-west), CASUD (south) and CIREST (east). Statistically, INSEE also distinguishes 5 sub-regions: north, west, south, east and the Hauts (highlands). Saint-Denis is the most populous municipality, with around 150,000 residents.
Which is the largest municipality in Reunion Island?
Saint-Paul is the largest municipality, at 241 km², nearly 10% of the island's total area. It stretches from the west coast (La Possession to south of La Saline) up to the summit of the Maïdo at 2,200m altitude. Saint-Joseph comes second, at around 179 km².
What is the largest town in Reunion Island?
Saint-Denis, the administrative capital, with around 150,000 residents. Saint-Paul, the second-largest town, has close to 106,000. Saint-Pierre, the economic capital of the south, has around 87,000. Le Tampon comes fourth, with 80,000 residents. Together, these four municipalities are home to nearly half of Reunion Island's population.
How much of the island is taken up by volcanoes?
The two volcanic massifs together cover more than three-quarters of the island. Piton des Neiges (dormant) occupies about 1,100 km² in the north-west, 44% of the territory, and is home to the three cirques of Cilaos, Mafate and Salazie. Piton de la Fournaise (active) covers about 830 km², 33% of the territory, in the south-east. The central plains and coastal strips make up the remaining 23%.
Why is Reunion Island considered an exceptional geographic concentration?
Across just 2,512 km², the island packs in a massif reaching 3,070m, an active volcano, three U-shaped cirques carved by erosion, primary forests listed as UNESCO World Heritage, coral lagoons, a dry savanna in the west and a humid tropical forest in the east. This density of landscapes explains the local expression "island-continent", despite its modest size.
Is Reunion Island a French department?
Yes. Reunion Island has been a French overseas department since the departmentalisation law of 19 March 1946. It's also a single-department region, making it the 5th largest French region by area outside mainland France. At the European level, Reunion Island is an outermost region (OMR) of the European Union, which gives it access to ERDF structural funds.
Is the island's surface area changing?
Marginally, yes. Major eruptions of Piton de la Fournaise whose lava flows reach the ocean occasionally extend the shoreline by a few hectares near Pointe du Tremblet. The April 2007 eruption and those of 2018 each added several hectares of new land. Over the long term, marine and river erosion wears away at the other side of the island, so the balance stays close to stable.
What is the population density of Reunion Island?
346 residents per km² on average, but the gap between coastal areas and the Hauts (highlands) is huge. Central Saint-Denis exceeds 4,000 residents/km², a density higher than Marseille. By contrast, the Mafate cirque has only a few hundred residents across 100 km², fewer than 5 residents/km². Land pressure on the coast pushes property prices up to levels close to Nice or Bordeaux.
Go further
Related pages on this site
Page updated in October 2026.