Eritrea Business Directory: ERI is the ISO 3 alphabet country code of Eritrea. Currency of Eritrea is Nkf, which has a short code of ERN. Capital of Eritrea is Asmara. Eritrea has the population of 5187948 and approximate area is 117600.00 square kilometers (or approx. 73076.64 square miles). Population density of Eritrea is approx. 44/Km2 (or approx. 27.3416/mile2)