Multiple Currencies

1. Go to the shopping setup page
2. Scroll down to plugins, or search for "multi currency plugin"
3. Select your desired currencies and add them to your currency list.
4. You have 2 options for exchange rate, see below

Fixed exchange rates

Fixed exchange rates allow you to sell your products in multiple currencies at a standard / fixed price, without your prices changing from day to day.

For example, a common exchange rate from NZD to AUD might be $1 for $1, or 0.90 per NZ$1

Live FX rates

Live FX rates will change the prices your customers pay hour to hour, day to day, for all currencies other than your base currency. Only the base currency is stable. 

An optional margin or 1% or 2% can be included, to ensure you receive enough to cover the cost of exchanging the currency back into your domestic currency (subject to your payment provider supporting this)

Forcing currency for certain countries. 

When setting up your shipping/freight options, you can lock a currency for a given shipping option. eg Lock Australia to AUD, and lock United States to USD, so that if anyone enters a delivery address in those countries, then they are forced to checkout in their own currency. 

Payment Methods

Remember that you must have sufficient payment methods to offer your customers in any currency. If a payment method does not support a given currency, then the payment method will not show. Paypal and Stripe a useful payment methods that can support most common currencies.