The exchange rate between the US dollar and the Nigerian naira fluctuates constantly. To determine how much a $100 Amazon gift card is in naira, one needs to check the current exchange rate.

Typically, financial institutions and currency exchange platforms provide the most accurate exchange rates. These rates are influenced by various factors such as economic conditions, market demand, and central bank policies.
When converting the $100 gift card to naira, it's important to note that the amount will vary depending on the specific exchange rate at the time of conversion. It could range from a relatively high amount if the naira is strong against the dollar to a lower amount if the dollar is more dominant in the market.
To get the exact figure, one should look up the latest exchange rate and multiply it by 100. This will give the equivalent value of the $100 Amazon gift card in Nigerian naira.