The Central Bank of Nigeria informs us of the rate we can sell NGN against the USD. At the time of writing (11 Sep, 2017), the USD/NGN rate that we can buy and sell USD/NGN is 355. It has been this way for over 6 months.
If you want to convert another currency into NGN (e.g. GBP to NGN), then we calculate the exchange rate by using the GBP-USD mid-market rate at the time you create your transfer, and multiplying the GBP-USD rate by the USD-NGN rate.
As an example this would look like:
- GBP-USD rate (at time of writing) - 1.34995
- USD-NGN rate - 355.00
- So, GBP-NGN rate - 1.34995 x 355.00 = 479.23225