Long Island is about 1.5 times bigger than Australian Capital Territory.

Australian Capital Territory is approximately 2,358 km² (910 sq mi), while Long Island is approximately 3,566 km² (1,377 sq mi), making Long Island 51% larger than Australian Capital Territory.
Tip: This to-scale comparison of Australian Capital Territory vs. Long Island uses the Mercator projection, which distorts the size of regions near the poles.

Compare further: Long Island vs. Australian Capital Territory

Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.