City size comparison

compared to

Boulder is about 2.6 times bigger than Sydney.

Sydney is approximately 27 sq km, while Boulder is approximately 70 sq km, making Boulder 161% larger than Sydney.
Tip: This to-scale comparison of Sydney vs. Boulder uses the Mercator projection, which distorts the size of regions near the poles.
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Compare further: Boulder vs. Sydney

Flip Comparison · See true size
See Boulder on top of Sydney
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Cost of Living Comparison · 7 categories - 2026 data
Sydney is 7.2% more expensive than Boulder
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