The map above shows Ohio and Ontario side by side at exactly the same scale, using equal-area projections, so their true relative sizes are preserved.
Ohio vs Ontario Geography
Land area: Ohio has a land area of 40,859 square miles (105,824 km²), while Ontario has 354,342 square miles (917,741 km²). Ontario's land area is 8.7 times (767%) larger than Ohio's.
Total area: Ohio: 44,826 square miles (116,098 km²) vs Ontario: 415,598 square miles (1,076,395 km²), including inland and coastal water. Ontario's total area is 9.3 times (827%) larger than Ohio's.
Length: Ohio is 291 miles (468 km) long from north to south; Ontario is 1,085 miles (1,747 km). Ontario's north-south length is 3.7 times (273%) longer than Ohio's.
Width: Ohio spans 317 miles (510 km) east to west; Ontario spans 1,013 miles (1,630 km). Ontario's east-west width is 3.2 times (220%) wider than Ohio's.
Highest point: Ohio's highest point is Campbell Hill at 1,547 feet (472 m); Ontario's is Ishpatina Ridge at 2,274 feet (693 m). Ishpatina Ridge is 727 feet higher than Campbell Hill.
Lowest point: Ohio's lowest point is Ohio River at 455 feet; Ontario's is Hudson Bay at 0 feet. Ontario's lowest point is 455 feet lower.
Ohio vs Ontario Population and History
Population: Ohio has a population of 11,883,304 (2024), while Ontario has 16,136,480 (2026). Ontario's population is 1.4 times (36%) larger than Ohio's.
Population density: Ohio: 290.8 people per square mile vs Ontario: 45.5. Ohio's population density is 6.4 times (539%) higher than Ontario's.
Biggest city: Ohio's biggest city is Columbus with 933,263 people; Ontario's is Toronto with 2,794,356. Toronto's population is 3.0 times (199%) larger than Columbus'.
Largest metro area: Ohio's largest metropolitan area is Cincinnati, OH-KY-IN metro area (2,302,815 people) vs Ontario's Toronto CMA (6,202,225). Toronto CMA's population is 2.7 times (169%) larger than Cincinnati, OH-KY-IN metro area's.
History: Ohio: Admitted to the Union on March 1, 1803, as the 17th state. Ontario: Joined Confederation on July 1, 1867, as one of the four founding provinces. In its current form, Ohio is the older of the two by 64 years.
Ohio vs Ontario Economy
GDP: Ohio's GDP is $923.1 billion (2024) vs Ontario's $873.9 billion. Ohio's economic output is 1.1 times (6%) larger than Ontario's.
GDP per capita: Ohio: $77,684 per person vs Ontario: $54,132. Ohio's GDP per capita is 1.4 times (44%) higher than Ontario's.
Official Websites
Ohio official website · Ontario official website
More Size Comparisons
All Ohio 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.