The Reserve Bank has more than tripled the number of currencies it now uses to measure the value of the New Zealand dollar, to 17 from five.
The central bank has also rebalanced the weight it attaches to the currencies of New Zealand's existing five trading partners, in favour of those which are Asian countries.
Australia is now number one in the basket of currencies, followed closely by the big new addition to the list - China.
The others are Singapore, South Korea, Malaysia, Thailand, Indonesia, India, Taiwan, Canada, Hong Kong, Vietnam and the Philippines.
Bancorp Treasury Services senior client advisor Peter Cavanaugh said the new trade-weighted-index, or TWI, better reflected New Zealand's trade focus.