The exchange rate between the US dollar and the Nigerian naira fluctuates constantly. To determine how much a $15 Google Play Card is in naira, one needs to check the current exchange rate.

Typically, you can find the exchange rate on financial news websites, currency exchange platforms, or even at local banks. Once you have the accurate exchange rate, you simply multiply it by 15. For example, if the exchange rate is 410 naira per dollar, then a $15 Google Play Card would be worth 15 * 410 = 6150 naira.

However, it's important to note that exchange rates are not static. They can change due to various economic factors such as inflation, interest rates, and global market conditions. So, it's advisable to check the latest rate just before making a purchase or conversion to get the most accurate value in naira for the $15 Google Play Card.