South Australia is about 1.4 times bigger than Texas.

Texas is approximately 678,052 sq km, while South Australia is approximately 984,321 km² (380,048 sq mi), making South Australia 45% larger than Texas.
Tip: This to-scale comparison of Texas vs. South Australia 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.