We assume that you have already logged into Zen Cart.
Click on the Localization link found on the main menu as shown below.

Then click on Currency link like the one below.

You can see that, there are already some currencies set up. By default US dollar is used in your store. Let’s add a new currency

Click on the new currency button, as shown above. Fill up the form, it is self explanatory.
Set the currency value relative to the default currency (US Dollars), optionally you can set this currency you are going to create as a default currency, by checking in the box shown below.

You have successfully added a currency to your store,  customers can now select the currency of their choice before processing payment. You can add as many currencies as you wish by following the same procedure. You can also edit or delete the currency already created by you by clicking on the respective buttons as shown below.

That’s it, you now know how to configure your currencies in Zen Cart.