Steve's Subnetting Cheat Sheet

BITS	MASK	MAX NO. HOSTS	MAX NO. SUBNETS
10	255.192.0.0	4194302	2
11	255.224.0.0	2097150	6
12	255.240.0.0	1048574	14
13	255.248.0.0	524286	30
14	255.252.0.0	262142	62
15	255.254.0.0	131070	126
16	255.255.0.0	655534	254
17	255.255.180.0	32766	510
18	255.255.192.0	16382	1022
19	255.255.224.0	8190	2046
20	255.255.240.0	4094	4094
21	255.255.248.0	2046	8190
22	255.255.252.0	1022	16382
23	255.255.254.0	510	32766
24	255.255.255.0	254	65534
25	255.255.255.128	126	131070
26	255.255.255.192	62	262142
27	255.255.255.224	30	524286
28	255.255.255.240	14	1048574
29	255.255.255.248	6	2097150
30	255.255.255.252	2	4194302