Which is bigger, Colosseum or Sydney Opera House?

Sydney Opera House is somewhat greater than Colosseum on height — about 1.4×. Both figures are typical values; the full range for each is in the table above.

How do Colosseums and Sydney Opera Houses compare on length?

Colosseum: 189 m. Sydney Opera House: 183 m. Colosseum and Sydney Opera House are near enough identical on length.

How do Colosseums and Sydney Opera Houses compare on width?

Colosseum: 156 m. Sydney Opera House: 120 m. Colosseum is somewhat greater than Sydney Opera House on width — about 1.3×.

Colosseum vs Sydney Opera House

Sydney Opera House is larger on height

Sydney Opera House is somewhat greater than Colosseum on height — about 1.4×.

Colosseum and Sydney Opera House can be compared on 4 measures. The figures below are typical adult or full-size values, with the larger of the two in bold.

Side by side

Larger value in bold. Ranges reflect genuine variation, not uncertainty.
	Colosseum	Sydney Opera House
Height	48 m	65 m
Length	189 m	183 m
Width	156 m	120 m
Area	24,000 m²	18,000 m²

What the numbers say

Sydney Opera House is somewhat greater than Colosseum on height — about 1.4×.
Colosseum and Sydney Opera House are near enough identical on length.
Colosseum is somewhat greater than Sydney Opera House on width — about 1.3×.
Colosseum is somewhat greater than Sydney Opera House on area — about 1.3×.

Height compared.

Sydney Opera House 65 m

Colosseum 48 m

Colosseum

The largest amphitheatre ever built, completed in Rome in AD 80.

Sydney Opera House

A multi-venue performing arts centre on Sydney Harbour, opened in 1973 and roofed with over a million tiles.

This is a comparison of published measurements, nothing more. It describes how two things differ on measures that have been recorded; it does not predict how they would fare against each other in any situation.

Common questions

Which is bigger, Colosseum or Sydney Opera House?: Sydney Opera House is somewhat greater than Colosseum on height — about 1.4×. Both figures are typical values; the full range for each is in the table above.
How do Colosseums and Sydney Opera Houses compare on length?: Colosseum: 189 m. Sydney Opera House: 183 m. Colosseum and Sydney Opera House are near enough identical on length.
How do Colosseums and Sydney Opera Houses compare on width?: Colosseum: 156 m. Sydney Opera House: 120 m. Colosseum is somewhat greater than Sydney Opera House on width — about 1.3×.

Sources

Wikidata — Wikimedia Foundation (CC0 1.0)

How these figures are compiled and checked