City size comparison

compared to

Sydney is about 2.6 times smaller than Boulder.

Boulder is approximately 70 sq km, while Sydney is approximately 27 sq km, making Sydney 38.35% the size of Boulder.
Tip: This to-scale comparison of Boulder vs. Sydney uses the Mercator projection, which distorts the size of regions near the poles.
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Compare further: Sydney vs. Boulder

Flip Comparison · See true size
See Sydney on top of Boulder
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Cost of Living Comparison · 7 categories - 2026 data
Boulder is 7.5% more expensive than Sydney
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