Geography · Great Lakes · Map

How much of Lake Erie is in Canada? About half (50.5%)

About half of Lake Erie is in Canada: 50.5% of its surface, 13,002 of 25,736 km². The United States holds 49.5%. The split is measured along the International Boundary Commission's surveyed border.

Published 9 Oct 2026 · Open Data Canada Sources International Boundary Commission · Natural Earth · NOAA GLERL

25,736 km²total surface, 4th-largest of the five Great Lakes
50.5%in Canada (13,002 km²), third of five by Canadian share
49.5%in the United States (12,734 km²)
14.5%of all Great Lakes surface Canada holds (89,664 km²)

Map of Lake Erie split along the Canada–U.S. boundary, shown as a dashed line. The Canadian part, 13,002 km² or 50.5%, is red; the U.S. part, 12,734 km², is navy.

Surface area on each side of the surveyed border. Source: International Boundary Commission boundary v1.3; Natural Earth lake outlines; ODC calculation in an equal-area projection (EPSG:3174).

Lake Erie splits almost exactly in half

Lake Erie is the closest split of the five. Measured along the surveyed boundary, Canada holds 13,002 km² and the United States 12,734 km², a gap of 268 km² on a 25,736 km² lake. A coarser cross-check using generalized country outlines puts Canada at 49.6%, so treat Erie as an even split rather than a Canadian majority. Erie's provisional September 2026 level was 17.9 cm above its 1918–2025 September average (tied 33rd-highest of 109 Septembers), and 17 cm higher than in September 2025.

All five lakes compared

Lake	Canada share	Canada km²	U.S. km²	Total km²
Superior	35.8%	29,460	52,851	82,311
Michigan	0.0%	0	57,541	57,541
Huron	61.0%	36,550	23,387	59,937
Erie	50.5%	13,002	12,734	25,736
Ontario	54.7%	10,653	8,810	19,464
All five lakes	36.6%	89,664	155,323	244,987

Common questions

How much of Lake Erie is in Canada? About half. Canada holds 50.5% of Lake Erie's surface, 13,002 of 25,736 km², and the United States holds 49.5%.

What percentage of Lake Erie is in Canada? 50.5% by the surveyed boundary. A coarser method gives 49.6%, so the honest answer is about half.

Is Lake Erie in Canada or the US? Both. The border runs close to the middle of the lake: the north half is in Ontario and the south half is in the United States.

Sources

International Boundary Commission, official digital boundary shapefile v1.3 (labelled for mapping use only, not to define the boundary)
Natural Earth, 10m lake outlines
NOAA Great Lakes Environmental Research Laboratory, lake-wide monthly water levels 1918–2026. September 2026 values are provisional; see 2026 Great Lakes water levels.

Method Each lake outline was cut along the surveyed boundary and measured in EPSG:3174 (NAD83 / Great Lakes and St. Lawrence Albers), an equal-area projection. Figures are the published split from our Great Lakes map.

Limits

Surface area only. The boundary data and lake outlines give no depth, water volume or per-country shoreline, so this page does not say how much of the lake's water each country holds.
A fresh rerun of the same calculation gives 12,985 km² Canadian and 12,750 km² U.S. (also 50.5%), a 17 km² difference from the published split above, from small differences in clipping. The share is unchanged.

All five lakes on one map: How much of each Great Lake is in Canada?

Other lakes: Lake Superior · Lake Michigan · Lake Huron · Lake Ontario

How much of Lake Erie is in Canada? About half (50.5%)

Lake Erie splits almost exactly in half

All five lakes compared

Common questions

The week in Canadian data, every Sunday.