The map above shows South Dakota and Western Australia side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
South Dakota vs Western Australia Geography
Land area: South Dakota has a land area of 75,808 square miles (196,342 km²), while Western Australia has 975,685 square miles (2,527,013 km²). Western Australia's land area is 12.9 times larger than South Dakota's.
Total area: South Dakota: 77,116 square miles (199,729 km²) vs Western Australia: 975,685 square miles (2,527,013 km²), including inland and coastal water. Western Australia's total area is 12.7 times larger than South Dakota's.
Length: South Dakota is 443 miles (712 km) long from north to south; Western Australia is 1,590 miles (2,558 km). Western Australia's north-south length is 3.6 times (259%) longer than South Dakota's.
Width: South Dakota spans 371 miles (597 km) east to west; Western Australia spans 1,286 miles (2,069 km). Western Australia's east-west width is 3.5 times (247%) wider than South Dakota's.
Highest point: South Dakota's highest point is Black Elk Peak at 7,198 feet (2,194 m); Western Australia's is Mount Meharry at 4,098 feet (1,249 m). Black Elk Peak is 3,100 feet higher than Mount Meharry.
Lowest point: South Dakota's lowest point is Big Stone Lake at 966 feet; Western Australia's is Indian Ocean at 0 feet. Western Australia's lowest point is 966 feet lower.
South Dakota vs Western Australia Population and History
Population: South Dakota has a population of 924,669 (2024), while Western Australia has 3,061,672 (2025). Western Australia's population is 3.3 times (231%) larger than South Dakota's.
Population density: South Dakota: 12.2 people per square mile vs Western Australia: 3.1. South Dakota's population density is 3.9 times (294%) higher than Western Australia's.
Largest metro area: South Dakota's largest metropolitan area is Sioux Falls, SD-MN metro area (308,266 people) vs Western Australia's Greater Perth (2,452,765). Greater Perth's population is 8.0 times (696%) larger than Sioux Falls, SD-MN metro area's.
History: South Dakota: Admitted to the Union on November 2, 1889, as the 40th state. Western Australia: Became an Australian state at Federation on January 1, 1901; founded as a colony in 1829. In its current form, South Dakota is the older of the two by 12 years.
South Dakota vs Western Australia Economy
GDP: South Dakota's GDP is $76.8 billion (2024) vs Western Australia's $304.6 billion. Western Australia's economic output is 4.0 times (297%) larger than South Dakota's.
GDP per capita: South Dakota: $83,052 per person vs Western Australia: $99,488. Western Australia's GDP per capita is 1.2 times (20%) higher than South Dakota's.
Official Websites
South Dakota official website · Western Australia official website
More Size Comparisons
All South Dakota size comparisons · All Western Australia size comparisons
Area, elevation and boundary figures come from official national statistics and US Census Bureau and Natural Earth boundary data; US state population, economic, county and tax figures come from the US Census Bureau, the Bureau of Economic Analysis and the Tax Foundation. Figures are rounded and for general reference.