Network Subnet Mask Cheat Sheet

 

Mask	# of Addresses	# Hosts	Netmask	Amount of a Class C
/ 30	4	2	255.255.255.252	1 / 64
/ 29	8	6	255.255.255.248	1 / 32
/ 28	16	14	255.255.255.240	1 / 16
/ 27	32	30	255.255.255.224	1 / 8
/ 26	64	62	255.255.255.192	1 / 4
/ 25	128	126	255.255.255.128	1 / 2
/ 24	256	254	255.255.255.0	1
/ 23	512	510	255.255.254.0	2
/ 22	1024	1022	255.255.252.0	4
/ 21	2048	2046	255.255.248.0	8
/ 20	4096	4094	255.255.240.0	16
/ 19	8192	8190	255.255.224.0	32
/ 18	16384	16382	255.255.192.0	64
/ 17	32768	32766	255.255.128.0	128
/ 16	65536	65534	255.255.0.0	256