Currency in Christmas Island Australian dollar (AUD A$). For 10 US dollars you can get 15.5 Australian dollars. For 100 US dollars you can get 155 Australian dollars. And the other way around: For 10 Australian dollars you can get 6.46 US dollars.
Prices:
If you're planning a trip to a specific region of the world, might it be cheaper than in Christmas Island? Check out prices in nearby countries: Cocos Islands, Singapore, Indonesia, Malaysia, and Brunei.