At the age of six, official primary education begins, and with it compulsory education. In 2018, Nigeria counted 22.4 million children enrolled in public elementary schools and 5.5 million in private schools. Recent data show that the gross enrollment rate in primary schools in Nigeria stood at 68.3 percent and North-Western states registered the highest figures. Data on the number of classrooms available in the country show that there was a deficit of over 230 thousand classrooms. Classes in Nigerian schools are, in fact, quite big. The most recent available data indicate that an elementary class in Nigeria has 51 pupils on average, with around 100 children per class in certain states. In Katsina, a state located in the North-West, the average was 101 pupils per class. Indeed, North-Western states record the highest deficit of classrooms in the whole country.
The official junior secondary education age in Nigeria is ages 12 to 14. In 2018, 6.8 million students were enrolled in both private and public lower secondary school institutions. The gross enrollment rate reached 54 percent. This rate shows the enrollment at any age, not only those in the officially established age groups. Nationwide, there were 13 thousand public schools for over five million students. Facilities available in schools differed remarkably based on ownership. Unsurprisingly, private institutions provided more facilities, such as more libraries, computer, playgrounds, and laboratories. Overall, the completion rate for upper secondary schools in Nigeria was higher among males, even if figures for both male and female students experienced an increase over the past years.
The official entrance age to upper secondary education in Nigeria is 15, with study duration being three years. Tertiary or post secondary education starts at 18. After lower secondary school, different forms of upper secondary school might follow. Students can choose a senior secondary, vocational, technical or business schools. University access requires a minimum score in different certificates, which can be achieved at the end of upper secondary education. In 2017, Nigerian universities counted 1.7 million undergraduate students and 234 thousand postgraduate students. The National Open University of Nigeria is the largest university in the country in terms of student numbers. The National Open University of Nigeria is the largest open and distance learning institute on the whole African continent.