Their size can range from very small mini-plasmids of less than a 1 kilobase pairs (Kbp), to very large megaplasmids of several megabase pairs (Mbp).
O seu tamaño pode ir de miniplásmidos moi pequenos de menos de 1 quilopares de bases (Kbp), a megaplásmidos moi grandes de varios pares de megabases (Mbp).