Since 1 US Dollar is equal to 1.678134 New Zealand Dollars, we could say that n United States Dollars are equal to 1.678134 times n New Zealand Dollars. In other words, we could use the following formula:
New Zealand Dollars = United States Dollars x 1.678134
For example, let's say that we want to convert 2.0 United States Dollars to New Zealand Dollars. Then, we just replace United States Dollars in the abovementioned formula with 2.0:
New Zealand Dollars = 2.0 x 1.678134
That is, 2.0 United States Dollars are equal to 3.356268 New Zealand Dollars.