Guinea-Bissau Business Directory: GNB is the ISO 3 alphabet country code of Guinea-Bissau. Currency of Guinea-Bissau is CFA, which has a short code of XOF. Capital of Guinea-Bissau is Bissau. Guinea-Bissau has the population of 1907268 and approximate area is 36125.00 square kilometers (or approx. 22448.075 square miles). Population density of Guinea-Bissau is approx. 52/Km2 (or approx. 32.3128/mile2)