The map above shows Iowa and South Dakota side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Iowa vs South Dakota Geography
Land area
- Iowa has a land area of 55,854 square miles (144,660 km²), while South Dakota has 75,808 square miles (196,342 km²).
- South Dakota's land area is 1.4 times (36%) larger than Iowa's.
Total area
- Iowa: 56,273 square miles (145,746 km²) vs South Dakota: 77,116 square miles (199,729 km²), including inland and coastal water.
- South Dakota's total area is 1.4 times (37%) larger than Iowa's.
Length
- Iowa is 216 miles (347 km) long from north to south; South Dakota is 443 miles (712 km).
- South Dakota's north-south length is 2.1 times (105%) longer than Iowa's.
Width
- Iowa spans 335 miles (539 km) east to west; South Dakota spans 371 miles (597 km).
- South Dakota's east-west width is 1.1 times (11%) wider than Iowa's.
Highest point
- Iowa's highest point is Hawkeye Point at 1,669 feet (509 m); South Dakota's is Black Elk Peak at 7,198 feet (2,194 m).
- Black Elk Peak is 5,529 feet higher than Hawkeye Point.
Lowest point
- Iowa's lowest point is Mississippi River at 480 feet; South Dakota's is Big Stone Lake at 966 feet.
- Iowa's lowest point is 486 feet lower.
Iowa vs South Dakota Population and History
Population
- Iowa has a population of 3,241,488 (2024), while South Dakota has 924,669 (2024).
- Iowa's population is 3.5 times (251%) larger than South Dakota's.
Population density
- Iowa: 58.0 people per square mile vs South Dakota: 12.2.
- Iowa's population density is 4.8 times (375%) higher than South Dakota's.
Biggest city
- Iowa's biggest city is Des Moines with 213,096 people; South Dakota's is Sioux Falls with 209,289.
- Des Moines and Sioux Falls have about the same population.
Largest metro area
- Iowa's largest metropolitan area is Omaha, NE-IA metro area (1,001,010 people) vs South Dakota's Sioux Falls, SD-MN metro area (308,266).
- Omaha, NE-IA metro area's population is 3.2 times (225%) larger than Sioux Falls, SD-MN metro area's.
History
- Iowa: Admitted to the Union on December 28, 1846, as the 29th state.
- South Dakota: Admitted to the Union on November 2, 1889, as the 40th state.
- In its current form, Iowa is the older of the two by 43 years.
Iowa vs South Dakota Economy
GDP
- Iowa's GDP is $265.8 billion (2024) vs South Dakota's $76.8 billion.
- Iowa's economic output is 3.5 times (246%) larger than South Dakota's.
GDP per capita
- Iowa: $81,998 per person vs South Dakota: $83,052.
- Iowa and South Dakota have about the same GDP per capita.
Average income
- Iowa: $65,225 vs South Dakota: $75,699 average income per person (per capita personal income).
- South Dakota's average income is 1.2 times (16%) higher than Iowa's.
Iowa vs South Dakota Counties
Number of counties
- Iowa has 99 counties, while South Dakota has 66.
- Iowa's county count is 1.5 times (50%) higher than South Dakota's.
Biggest county by area
- Iowa's largest county is Kossuth County at 973 square miles; South Dakota's is Meade County at 3,471 square miles.
- Meade County's land area is 3.6 times (257%) larger than Kossuth County's.
Smallest county by area
- Iowa: Dickinson County (381 sq mi) vs South Dakota: Clay County (412 sq mi).
- Clay County's land area is 1.1 times (8%) larger than Dickinson County's.
Most populous county
- Iowa: Polk County (516,185 people) vs South Dakota: Minnehaha County (208,639 people).
- Polk County's population is 2.5 times (147%) larger than Minnehaha County's.
Least populous county
- Iowa: Adams County (3,606 people) vs South Dakota: Jones County (874 people).
- Adams County's population is 4.1 times (313%) larger than Jones County's.
Richest county
- Iowa: Mitchell County ($98,211 per capita income) vs South Dakota: Union County ($146,712).
- Union County's income is 1.5 times (49%) richer than Mitchell County's.
Poorest county
- Iowa: Decatur County ($46,134 per capita income) vs South Dakota: Ziebach County ($32,778).
- Decatur County's income is 1.4 times (41%) richer than Ziebach County's.
Iowa vs South Dakota Taxes
State income tax
- Iowa has a top income tax rate of 3.8%, while South Dakota has no state income tax.
- Iowa's top rate is 3.8 percentage points higher.
Property tax
- Iowa: 1.29% effective rate vs South Dakota: 1.02% of home value per year.
- Iowa's rate is 0.27 percentage points higher.
Sales tax
- Iowa: 6.94% combined state and average local rate vs South Dakota: 6.11%.
- Iowa's combined rate is 0.83 percentage points higher.
Official Websites
Iowa official website · South Dakota official website
Download the Iowa vs South Dakota Size Comparison Map for free
To download the map, right-click the image above (or press and hold on a phone or tablet) and choose Save image as. The map is free to use anywhere, including on your own website or in print, as long as you credit it with a link back to this page or to BrilliantMaps.com.
More Size Comparisons
All Iowa size comparisons · All South Dakota 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.