Payments with IOTA are calculated as Mega Iotas (Mi). You can use a calculator at the following address:
https://explorer.iota.org/chrysalis/currency-converter/
The exchange rate is calculated instantly when you generate the IOTA address to which the payment must be made before one hour.
We use CoinMarketCap to calculate the exchange value from USD to IOTA. Please note that the amount of Mi tokens is a bit higher while trying to pay invoices with Netz0. The reason is we add a 10% overhead to the token calculation as stated in the initial IOTA announcement.
Accepting cryptocurrencies comes with a risk while converting amounts to USD and while IOTA is very stable in fluctuations some of our margins and products are exceptionally low which means that any small decrease in the value after receiving it would result in a financial loss.
Instead of not offering this payment option we believe in adopting new and modern technologies. Crypto payments are the future of Internet payments, and we are constantly improving this payment method. Even if we had a method to instantly convert tokens back to USD in real-time in a secure and trustable way, the market is still very new and there are many financial fees and risks associated with accepting and converting cryptocurrencies to standard fiat currency. If this changes in the future, we will remove the 10% fluctuation fee.
The fee is not added to your invoices or orders, only to the amount of tokens that need to be transferred while using IOTA. You can switch the payment method in your invoice at any time.