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

Exchange rates are influenced by various factors such as economic conditions, central bank policies, and market sentiment. Financial institutions and currency exchange platforms provide the latest rates.
By looking up the prevailing exchange rate and multiplying it by 100, one can calculate the approximate value of the $100 Amazon gift card in naira. This value will change from day to day, so it's essential to get the most recent rate for an accurate conversion.