Oahu is about 1.8 times smaller than Rhode Island.

Rhode Island is approximately 2,706 sq km, while Oahu is approximately 1,545 km² (597 sq mi), making Oahu 57.1% the size of Rhode Island.
Tip: This to-scale comparison of Rhode Island vs. Oahu uses the Mercator projection, which distorts the size of regions near the poles.
Our free app, MapSize by MyLifeElsewhere — compare any two places, to scale on your mobile device.