CIDR	Hosts	Netmask	# of subnets
/33	0	...255.255.255.255&½	∞?
/32	1	255.255.255.255	256
/31	2	255.255.255.254	128
/30	4	255.255.255.252	64
/29	8	255.255.255.248	32
/28	16	255.255.255.240	16
/27	32	255.255.255.224	8
/26	64	255.255.255.192	4
/25	128	255.255.255.128	2
/24	256	255.255.255.0	1
/23	512	255.255.254.0	128
/22	1,024	255.255.252.0	64
/21	2,048	255.255.248.0	32
/20	4,096	255.255.240.0	16
/19	8,192	255.255.224.0	8
/18	16,384	255.255.192.0	4
/17	32,768	255.255.128.0	2
/16	65,536	255.255.0.0	1
/15	131,072	255.254.0.0	128
/14	262,144	255.252.0.0	64
/13	524,288	255.248.0.0	32
/12	1,048,576	255.240.0.0	16
/11	2,097,152	255.224.0.0	8
/10	4,194,304	255.192.0.0	4
/9	8,388,608	255.128.0.0	2
/8	16,777,216	255.0.0.0	1
/7	33,554,432	254.0.0.0	128
/6	67,108,864	252.0.0.0	64
/5	134,217,728	248.0.0.0	32
/4	268,435,456	240.0.0.0	16
/3	536,870,912	224.0.0.0	8
/2	1,073,741,824	192.0.0.0	4
/1	2,147,483,648	128.0.0.0	2
/0	4,294,967,296	0.0.0.0	1