The map above shows Missouri and Ontario side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Missouri vs Ontario Geography
Land area: Missouri has a land area of 68,746 square miles (178,052 km²), while Ontario has 354,342 square miles (917,741 km²). Ontario's land area is 5.2 times (415%) larger than Missouri's.
Total area: Missouri: 69,707 square miles (180,540 km²) vs Ontario: 415,598 square miles (1,076,395 km²), including inland and coastal water. Ontario's total area is 6.0 times (496%) larger than Missouri's.
Length: Missouri is 328 miles (529 km) long from north to south; Ontario is 1,085 miles (1,747 km). Ontario's north-south length is 3.3 times (231%) longer than Missouri's.
Width: Missouri spans 437 miles (703 km) east to west; Ontario spans 1,013 miles (1,630 km). Ontario's east-west width is 2.3 times (132%) wider than Missouri's.
Highest point: Missouri's highest point is Taum Sauk Mountain at 1,771 feet (540 m); Ontario's is Ishpatina Ridge at 2,274 feet (693 m). Ishpatina Ridge is 503 feet higher than Taum Sauk Mountain.
Lowest point: Missouri's lowest point is St. Francis River at 230 feet; Ontario's is Hudson Bay at 0 feet. Ontario's lowest point is 230 feet lower.
Missouri vs Ontario Population and History
Population: Missouri has a population of 6,245,466 (2024), while Ontario has 16,136,480 (2026). Ontario's population is 2.6 times (158%) larger than Missouri's.
Population density: Missouri: 90.8 people per square mile vs Ontario: 45.5. Missouri's population density is 2.0 times (100%) higher than Ontario's.
Biggest city: Missouri's biggest city is Kansas City with 516,032 people; Ontario's is Toronto with 2,794,356. Toronto's population is 5.4 times (442%) larger than Kansas City's.
Largest metro area: Missouri's largest metropolitan area is St. Louis, MO-IL metro area (2,811,927 people) vs Ontario's Toronto CMA (6,202,225). Toronto CMA's population is 2.2 times (121%) larger than St. Louis, MO-IL metro area's.
History: Missouri: Admitted to the Union on August 10, 1821, as the 24th state. Ontario: Joined Confederation on July 1, 1867, as one of the four founding provinces. In its current form, Missouri is the older of the two by 46 years.
Missouri vs Ontario Economy
GDP: Missouri's GDP is $448.7 billion (2024) vs Ontario's $873.9 billion. Ontario's economic output is 1.9 times (95%) larger than Missouri's.
GDP per capita: Missouri: $71,846 per person vs Ontario: $54,132. Missouri's GDP per capita is 1.3 times (33%) higher than Ontario's.
Official Websites
Missouri official website · Ontario official website
More Size Comparisons
All Missouri size comparisons · All Ontario 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.