The total amount of the universe that is made up of black holes is not precisely known, but it is estimated to be relatively small. However, it is important to note that there are many different types of black holes, ranging from small stellar black holes to supermassive black holes at the centers of galaxies. The contribution of black holes to the total mass-energy of the universe is still an active area of research and is influenced by various factors such as the number and mass distribution of black holes and the overall dynamics of the universe.