It works in the same way as well-known Economist's 'Big Mag Index', which measures purchasing power parity by comparing the price of a Big Mac in several different countries.
Australia is the fourth-cheapest place to buy an iPad, at US$507 ($604.87). One New Zealand dollar currently trades for about 89 Australian cents.
Comparing the price of iPads, the New Zealand dollar is worth about 83 Australian cents, which would suggest the two currencies are trading at a fair value.
An iPad in the United States is similarly cheap, costing about US$499 ($595.32) and one dollar in New Zealand is worth about $0.81 in the United States, compared with the current trading value of $0.84.
However, in China, where many iPads are produced, the Kiwi dollar appears expensive. An iPad costs US$602.52 ($719.40), suggesting the two currencies share a similar value.
In the current foreign exchange market, the New Zealand dollar is worth about 5.13 Yuan.
New Zealand's value against the UK Pound Sterling tells the opposite story, where it costs US$639 ($762.35), five per cent more expensive than in New Zealand. One New Zealand dollar is currently worth a significantly cheaper 52 pence.
The survey does not take into account factors such as taxes and freight costs, and CommSec chief economist Craig James says the survey is a fairly light-hearted comparison of the world's currencies.