An exchange rate is usually presented in pairs. You’ll have one currency paired with another one. What this means is the first currency in the pair is the base and the value should be $1. The next figure is how much of that currency it will take to purchase $1 of the base currency.
Here is an example of how to convert currencies: If the EUR/AUD currency pair is 1.56 (just an example), it only means that 1 Euro equals to 1.56 Australian Dollar. Therefore, it shows much AUD (second currency) is needed to buy a single unit of EUR (first currency).
To calculate how much first currency (EUR) you’ll need to purchase the second currency (AUD), you will use this formula: 1/exchange rate.
With the example provided above, it will be 1/1.56=0.6410. It means that it costs 0.6410 Euros to purchase 1 Australian Dollar.