Irvine is about 3.7 times smaller than Toronto.

Toronto is approximately 630 sq km, while Irvine (map shows its 24 named neighbourhoods; the area covers the whole city) is approximately 170 sq km, making Irvine 26.97% the size of Toronto.
Tip: This to-scale comparison of Toronto vs. Irvine uses the Mercator projection, which distorts the size of regions near the poles.
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