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IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network157.0.0.0/11
Usable hosts2,097,150
Subnet mask255.224.0.0
Addresses2,097,152
Network address
157.0.0.0
Broadcast address
157.31.255.255
First usable
157.0.0.1
Last usable
157.31.255.254
Usable hosts
2,097,150 (2,097,152 less the network and broadcast addresses)
Subnet mask
255.224.0.0
Wildcard mask
0.31.255.255 (Cisco ACLs, OSPF)
Prefix length
/11
Type
Public public
Old class
B (default /16)
As numbers
Hex 9D000000 · Integer 2634022912 to 2636120063
Reverse DNS zones
0.157.in-addr.arpa
1.157.in-addr.arpa
2.157.in-addr.arpa
3.157.in-addr.arpa
4.157.in-addr.arpa
5.157.in-addr.arpa
6.157.in-addr.arpa
7.157.in-addr.arpa
8.157.in-addr.arpa
9.157.in-addr.arpa
10.157.in-addr.arpa
11.157.in-addr.arpa
12.157.in-addr.arpa
13.157.in-addr.arpa
14.157.in-addr.arpa
15.157.in-addr.arpa
and 16 more
/11 is not on a 8-bit boundary, so it takes 32 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011101.00000000.00000000.00000000157.0.0.0
Subnet mask11111111.11100000.00000000.00000000255.224.0.0
Network10011101.00000000.00000000.00000000157.0.0.0
Broadcast10011101.00011111.11111111.11111111157.31.255.255
Split into smaller subnets/20
/12 (2)/13 (4)/14 (8)/15 (16)/16 (32)/17 (64)/18 (128)/19 (256)/20 (512)/21 (1,024)/22 (2,048)/23 (4,096)

157.0.0.0/11 makes 512 subnets of /20; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1157.0.0.0/20157.0.0.1 to 157.0.15.254157.0.15.2554,094
2157.0.16.0/20157.0.16.1 to 157.0.31.254157.0.31.2554,094
3157.0.32.0/20157.0.32.1 to 157.0.47.254157.0.47.2554,094
4157.0.48.0/20157.0.48.1 to 157.0.63.254157.0.63.2554,094
5157.0.64.0/20157.0.64.1 to 157.0.79.254157.0.79.2554,094
6157.0.80.0/20157.0.80.1 to 157.0.95.254157.0.95.2554,094
7157.0.96.0/20157.0.96.1 to 157.0.111.254157.0.111.2554,094
8157.0.112.0/20157.0.112.1 to 157.0.127.254157.0.127.2554,094
9157.0.128.0/20157.0.128.1 to 157.0.143.254157.0.143.2554,094
10157.0.144.0/20157.0.144.1 to 157.0.159.254157.0.159.2554,094
11157.0.160.0/20157.0.160.1 to 157.0.175.254157.0.175.2554,094
12157.0.176.0/20157.0.176.1 to 157.0.191.254157.0.191.2554,094
13157.0.192.0/20157.0.192.1 to 157.0.207.254157.0.207.2554,094
14157.0.208.0/20157.0.208.1 to 157.0.223.254157.0.223.2554,094
15157.0.224.0/20157.0.224.1 to 157.0.239.254157.0.239.2554,094
16157.0.240.0/20157.0.240.1 to 157.0.255.254157.0.255.2554,094
17157.1.0.0/20157.1.0.1 to 157.1.15.254157.1.15.2554,094
18157.1.16.0/20157.1.16.1 to 157.1.31.254157.1.31.2554,094
19157.1.32.0/20157.1.32.1 to 157.1.47.254157.1.47.2554,094
20157.1.48.0/20157.1.48.1 to 157.1.63.254157.1.63.2554,094
21157.1.64.0/20157.1.64.1 to 157.1.79.254157.1.79.2554,094
22157.1.80.0/20157.1.80.1 to 157.1.95.254157.1.95.2554,094
23157.1.96.0/20157.1.96.1 to 157.1.111.254157.1.111.2554,094
24157.1.112.0/20157.1.112.1 to 157.1.127.254157.1.127.2554,094
25157.1.128.0/20157.1.128.1 to 157.1.143.254157.1.143.2554,094
26157.1.144.0/20157.1.144.1 to 157.1.159.254157.1.159.2554,094
27157.1.160.0/20157.1.160.1 to 157.1.175.254157.1.175.2554,094
28157.1.176.0/20157.1.176.1 to 157.1.191.254157.1.191.2554,094
29157.1.192.0/20157.1.192.1 to 157.1.207.254157.1.207.2554,094
30157.1.208.0/20157.1.208.1 to 157.1.223.254157.1.223.2554,094
31157.1.224.0/20157.1.224.1 to 157.1.239.254157.1.239.2554,094
32157.1.240.0/20157.1.240.1 to 157.1.255.254157.1.255.2554,094
33157.2.0.0/20157.2.0.1 to 157.2.15.254157.2.15.2554,094
34157.2.16.0/20157.2.16.1 to 157.2.31.254157.2.31.2554,094
35157.2.32.0/20157.2.32.1 to 157.2.47.254157.2.47.2554,094
36157.2.48.0/20157.2.48.1 to 157.2.63.254157.2.63.2554,094
37157.2.64.0/20157.2.64.1 to 157.2.79.254157.2.79.2554,094
38157.2.80.0/20157.2.80.1 to 157.2.95.254157.2.95.2554,094
39157.2.96.0/20157.2.96.1 to 157.2.111.254157.2.111.2554,094
40157.2.112.0/20157.2.112.1 to 157.2.127.254157.2.127.2554,094
41157.2.128.0/20157.2.128.1 to 157.2.143.254157.2.143.2554,094
42157.2.144.0/20157.2.144.1 to 157.2.159.254157.2.159.2554,094
43157.2.160.0/20157.2.160.1 to 157.2.175.254157.2.175.2554,094
44157.2.176.0/20157.2.176.1 to 157.2.191.254157.2.191.2554,094
45157.2.192.0/20157.2.192.1 to 157.2.207.254157.2.207.2554,094
46157.2.208.0/20157.2.208.1 to 157.2.223.254157.2.223.2554,094
47157.2.224.0/20157.2.224.1 to 157.2.239.254157.2.239.2554,094
48157.2.240.0/20157.2.240.1 to 157.2.255.254157.2.255.2554,094
49157.3.0.0/20157.3.0.1 to 157.3.15.254157.3.15.2554,094
50157.3.16.0/20157.3.16.1 to 157.3.31.254157.3.31.2554,094
51157.3.32.0/20157.3.32.1 to 157.3.47.254157.3.47.2554,094
52157.3.48.0/20157.3.48.1 to 157.3.63.254157.3.63.2554,094
53157.3.64.0/20157.3.64.1 to 157.3.79.254157.3.79.2554,094
54157.3.80.0/20157.3.80.1 to 157.3.95.254157.3.95.2554,094
55157.3.96.0/20157.3.96.1 to 157.3.111.254157.3.111.2554,094
56157.3.112.0/20157.3.112.1 to 157.3.127.254157.3.127.2554,094
57157.3.128.0/20157.3.128.1 to 157.3.143.254157.3.143.2554,094
58157.3.144.0/20157.3.144.1 to 157.3.159.254157.3.159.2554,094
59157.3.160.0/20157.3.160.1 to 157.3.175.254157.3.175.2554,094
60157.3.176.0/20157.3.176.1 to 157.3.191.254157.3.191.2554,094
61157.3.192.0/20157.3.192.1 to 157.3.207.254157.3.207.2554,094
62157.3.208.0/20157.3.208.1 to 157.3.223.254157.3.223.2554,094
63157.3.224.0/20157.3.224.1 to 157.3.239.254157.3.239.2554,094
64157.3.240.0/20157.3.240.1 to 157.3.255.254157.3.255.2554,094
65157.4.0.0/20157.4.0.1 to 157.4.15.254157.4.15.2554,094
66157.4.16.0/20157.4.16.1 to 157.4.31.254157.4.31.2554,094
67157.4.32.0/20157.4.32.1 to 157.4.47.254157.4.47.2554,094
68157.4.48.0/20157.4.48.1 to 157.4.63.254157.4.63.2554,094
69157.4.64.0/20157.4.64.1 to 157.4.79.254157.4.79.2554,094
70157.4.80.0/20157.4.80.1 to 157.4.95.254157.4.95.2554,094
71157.4.96.0/20157.4.96.1 to 157.4.111.254157.4.111.2554,094
72157.4.112.0/20157.4.112.1 to 157.4.127.254157.4.127.2554,094
73157.4.128.0/20157.4.128.1 to 157.4.143.254157.4.143.2554,094
74157.4.144.0/20157.4.144.1 to 157.4.159.254157.4.159.2554,094
75157.4.160.0/20157.4.160.1 to 157.4.175.254157.4.175.2554,094
76157.4.176.0/20157.4.176.1 to 157.4.191.254157.4.191.2554,094
77157.4.192.0/20157.4.192.1 to 157.4.207.254157.4.207.2554,094
78157.4.208.0/20157.4.208.1 to 157.4.223.254157.4.223.2554,094
79157.4.224.0/20157.4.224.1 to 157.4.239.254157.4.239.2554,094
80157.4.240.0/20157.4.240.1 to 157.4.255.254157.4.255.2554,094
81157.5.0.0/20157.5.0.1 to 157.5.15.254157.5.15.2554,094
82157.5.16.0/20157.5.16.1 to 157.5.31.254157.5.31.2554,094
83157.5.32.0/20157.5.32.1 to 157.5.47.254157.5.47.2554,094
84157.5.48.0/20157.5.48.1 to 157.5.63.254157.5.63.2554,094
85157.5.64.0/20157.5.64.1 to 157.5.79.254157.5.79.2554,094
86157.5.80.0/20157.5.80.1 to 157.5.95.254157.5.95.2554,094
87157.5.96.0/20157.5.96.1 to 157.5.111.254157.5.111.2554,094
88157.5.112.0/20157.5.112.1 to 157.5.127.254157.5.127.2554,094
89157.5.128.0/20157.5.128.1 to 157.5.143.254157.5.143.2554,094
90157.5.144.0/20157.5.144.1 to 157.5.159.254157.5.159.2554,094
91157.5.160.0/20157.5.160.1 to 157.5.175.254157.5.175.2554,094
92157.5.176.0/20157.5.176.1 to 157.5.191.254157.5.191.2554,094
93157.5.192.0/20157.5.192.1 to 157.5.207.254157.5.207.2554,094
94157.5.208.0/20157.5.208.1 to 157.5.223.254157.5.223.2554,094
95157.5.224.0/20157.5.224.1 to 157.5.239.254157.5.239.2554,094
96157.5.240.0/20157.5.240.1 to 157.5.255.254157.5.255.2554,094
97157.6.0.0/20157.6.0.1 to 157.6.15.254157.6.15.2554,094
98157.6.16.0/20157.6.16.1 to 157.6.31.254157.6.31.2554,094
99157.6.32.0/20157.6.32.1 to 157.6.47.254157.6.47.2554,094
100157.6.48.0/20157.6.48.1 to 157.6.63.254157.6.63.2554,094
101157.6.64.0/20157.6.64.1 to 157.6.79.254157.6.79.2554,094
102157.6.80.0/20157.6.80.1 to 157.6.95.254157.6.95.2554,094
103157.6.96.0/20157.6.96.1 to 157.6.111.254157.6.111.2554,094
104157.6.112.0/20157.6.112.1 to 157.6.127.254157.6.127.2554,094
105157.6.128.0/20157.6.128.1 to 157.6.143.254157.6.143.2554,094
106157.6.144.0/20157.6.144.1 to 157.6.159.254157.6.159.2554,094
107157.6.160.0/20157.6.160.1 to 157.6.175.254157.6.175.2554,094
108157.6.176.0/20157.6.176.1 to 157.6.191.254157.6.191.2554,094
109157.6.192.0/20157.6.192.1 to 157.6.207.254157.6.207.2554,094
110157.6.208.0/20157.6.208.1 to 157.6.223.254157.6.223.2554,094
111157.6.224.0/20157.6.224.1 to 157.6.239.254157.6.239.2554,094
112157.6.240.0/20157.6.240.1 to 157.6.255.254157.6.255.2554,094
113157.7.0.0/20157.7.0.1 to 157.7.15.254157.7.15.2554,094
114157.7.16.0/20157.7.16.1 to 157.7.31.254157.7.31.2554,094
115157.7.32.0/20157.7.32.1 to 157.7.47.254157.7.47.2554,094
116157.7.48.0/20157.7.48.1 to 157.7.63.254157.7.63.2554,094
117157.7.64.0/20157.7.64.1 to 157.7.79.254157.7.79.2554,094
118157.7.80.0/20157.7.80.1 to 157.7.95.254157.7.95.2554,094
119157.7.96.0/20157.7.96.1 to 157.7.111.254157.7.111.2554,094
120157.7.112.0/20157.7.112.1 to 157.7.127.254157.7.127.2554,094
121157.7.128.0/20157.7.128.1 to 157.7.143.254157.7.143.2554,094
122157.7.144.0/20157.7.144.1 to 157.7.159.254157.7.159.2554,094
123157.7.160.0/20157.7.160.1 to 157.7.175.254157.7.175.2554,094
124157.7.176.0/20157.7.176.1 to 157.7.191.254157.7.191.2554,094
125157.7.192.0/20157.7.192.1 to 157.7.207.254157.7.207.2554,094
126157.7.208.0/20157.7.208.1 to 157.7.223.254157.7.223.2554,094
127157.7.224.0/20157.7.224.1 to 157.7.239.254157.7.239.2554,094
128157.7.240.0/20157.7.240.1 to 157.7.255.254157.7.255.2554,094
129157.8.0.0/20157.8.0.1 to 157.8.15.254157.8.15.2554,094
130157.8.16.0/20157.8.16.1 to 157.8.31.254157.8.31.2554,094
131157.8.32.0/20157.8.32.1 to 157.8.47.254157.8.47.2554,094
132157.8.48.0/20157.8.48.1 to 157.8.63.254157.8.63.2554,094
133157.8.64.0/20157.8.64.1 to 157.8.79.254157.8.79.2554,094
134157.8.80.0/20157.8.80.1 to 157.8.95.254157.8.95.2554,094
135157.8.96.0/20157.8.96.1 to 157.8.111.254157.8.111.2554,094
136157.8.112.0/20157.8.112.1 to 157.8.127.254157.8.127.2554,094
137157.8.128.0/20157.8.128.1 to 157.8.143.254157.8.143.2554,094
138157.8.144.0/20157.8.144.1 to 157.8.159.254157.8.159.2554,094
139157.8.160.0/20157.8.160.1 to 157.8.175.254157.8.175.2554,094
140157.8.176.0/20157.8.176.1 to 157.8.191.254157.8.191.2554,094
141157.8.192.0/20157.8.192.1 to 157.8.207.254157.8.207.2554,094
142157.8.208.0/20157.8.208.1 to 157.8.223.254157.8.223.2554,094
143157.8.224.0/20157.8.224.1 to 157.8.239.254157.8.239.2554,094
144157.8.240.0/20157.8.240.1 to 157.8.255.254157.8.255.2554,094
145157.9.0.0/20157.9.0.1 to 157.9.15.254157.9.15.2554,094
146157.9.16.0/20157.9.16.1 to 157.9.31.254157.9.31.2554,094
147157.9.32.0/20157.9.32.1 to 157.9.47.254157.9.47.2554,094
148157.9.48.0/20157.9.48.1 to 157.9.63.254157.9.63.2554,094
149157.9.64.0/20157.9.64.1 to 157.9.79.254157.9.79.2554,094
150157.9.80.0/20157.9.80.1 to 157.9.95.254157.9.95.2554,094
151157.9.96.0/20157.9.96.1 to 157.9.111.254157.9.111.2554,094
152157.9.112.0/20157.9.112.1 to 157.9.127.254157.9.127.2554,094
153157.9.128.0/20157.9.128.1 to 157.9.143.254157.9.143.2554,094
154157.9.144.0/20157.9.144.1 to 157.9.159.254157.9.159.2554,094
155157.9.160.0/20157.9.160.1 to 157.9.175.254157.9.175.2554,094
156157.9.176.0/20157.9.176.1 to 157.9.191.254157.9.191.2554,094
157157.9.192.0/20157.9.192.1 to 157.9.207.254157.9.207.2554,094
158157.9.208.0/20157.9.208.1 to 157.9.223.254157.9.223.2554,094
159157.9.224.0/20157.9.224.1 to 157.9.239.254157.9.239.2554,094
160157.9.240.0/20157.9.240.1 to 157.9.255.254157.9.255.2554,094
161157.10.0.0/20157.10.0.1 to 157.10.15.254157.10.15.2554,094
162157.10.16.0/20157.10.16.1 to 157.10.31.254157.10.31.2554,094
163157.10.32.0/20157.10.32.1 to 157.10.47.254157.10.47.2554,094
164157.10.48.0/20157.10.48.1 to 157.10.63.254157.10.63.2554,094
165157.10.64.0/20157.10.64.1 to 157.10.79.254157.10.79.2554,094
166157.10.80.0/20157.10.80.1 to 157.10.95.254157.10.95.2554,094
167157.10.96.0/20157.10.96.1 to 157.10.111.254157.10.111.2554,094
168157.10.112.0/20157.10.112.1 to 157.10.127.254157.10.127.2554,094
169157.10.128.0/20157.10.128.1 to 157.10.143.254157.10.143.2554,094
170157.10.144.0/20157.10.144.1 to 157.10.159.254157.10.159.2554,094
171157.10.160.0/20157.10.160.1 to 157.10.175.254157.10.175.2554,094
172157.10.176.0/20157.10.176.1 to 157.10.191.254157.10.191.2554,094
173157.10.192.0/20157.10.192.1 to 157.10.207.254157.10.207.2554,094
174157.10.208.0/20157.10.208.1 to 157.10.223.254157.10.223.2554,094
175157.10.224.0/20157.10.224.1 to 157.10.239.254157.10.239.2554,094
176157.10.240.0/20157.10.240.1 to 157.10.255.254157.10.255.2554,094
177157.11.0.0/20157.11.0.1 to 157.11.15.254157.11.15.2554,094
178157.11.16.0/20157.11.16.1 to 157.11.31.254157.11.31.2554,094
179157.11.32.0/20157.11.32.1 to 157.11.47.254157.11.47.2554,094
180157.11.48.0/20157.11.48.1 to 157.11.63.254157.11.63.2554,094
181157.11.64.0/20157.11.64.1 to 157.11.79.254157.11.79.2554,094
182157.11.80.0/20157.11.80.1 to 157.11.95.254157.11.95.2554,094
183157.11.96.0/20157.11.96.1 to 157.11.111.254157.11.111.2554,094
184157.11.112.0/20157.11.112.1 to 157.11.127.254157.11.127.2554,094
185157.11.128.0/20157.11.128.1 to 157.11.143.254157.11.143.2554,094
186157.11.144.0/20157.11.144.1 to 157.11.159.254157.11.159.2554,094
187157.11.160.0/20157.11.160.1 to 157.11.175.254157.11.175.2554,094
188157.11.176.0/20157.11.176.1 to 157.11.191.254157.11.191.2554,094
189157.11.192.0/20157.11.192.1 to 157.11.207.254157.11.207.2554,094
190157.11.208.0/20157.11.208.1 to 157.11.223.254157.11.223.2554,094
191157.11.224.0/20157.11.224.1 to 157.11.239.254157.11.239.2554,094
192157.11.240.0/20157.11.240.1 to 157.11.255.254157.11.255.2554,094
193157.12.0.0/20157.12.0.1 to 157.12.15.254157.12.15.2554,094
194157.12.16.0/20157.12.16.1 to 157.12.31.254157.12.31.2554,094
195157.12.32.0/20157.12.32.1 to 157.12.47.254157.12.47.2554,094
196157.12.48.0/20157.12.48.1 to 157.12.63.254157.12.63.2554,094
197157.12.64.0/20157.12.64.1 to 157.12.79.254157.12.79.2554,094
198157.12.80.0/20157.12.80.1 to 157.12.95.254157.12.95.2554,094
199157.12.96.0/20157.12.96.1 to 157.12.111.254157.12.111.2554,094
200157.12.112.0/20157.12.112.1 to 157.12.127.254157.12.127.2554,094
201157.12.128.0/20157.12.128.1 to 157.12.143.254157.12.143.2554,094
202157.12.144.0/20157.12.144.1 to 157.12.159.254157.12.159.2554,094
203157.12.160.0/20157.12.160.1 to 157.12.175.254157.12.175.2554,094
204157.12.176.0/20157.12.176.1 to 157.12.191.254157.12.191.2554,094
205157.12.192.0/20157.12.192.1 to 157.12.207.254157.12.207.2554,094
206157.12.208.0/20157.12.208.1 to 157.12.223.254157.12.223.2554,094
207157.12.224.0/20157.12.224.1 to 157.12.239.254157.12.239.2554,094
208157.12.240.0/20157.12.240.1 to 157.12.255.254157.12.255.2554,094
209157.13.0.0/20157.13.0.1 to 157.13.15.254157.13.15.2554,094
210157.13.16.0/20157.13.16.1 to 157.13.31.254157.13.31.2554,094
211157.13.32.0/20157.13.32.1 to 157.13.47.254157.13.47.2554,094
212157.13.48.0/20157.13.48.1 to 157.13.63.254157.13.63.2554,094
213157.13.64.0/20157.13.64.1 to 157.13.79.254157.13.79.2554,094
214157.13.80.0/20157.13.80.1 to 157.13.95.254157.13.95.2554,094
215157.13.96.0/20157.13.96.1 to 157.13.111.254157.13.111.2554,094
216157.13.112.0/20157.13.112.1 to 157.13.127.254157.13.127.2554,094
217157.13.128.0/20157.13.128.1 to 157.13.143.254157.13.143.2554,094
218157.13.144.0/20157.13.144.1 to 157.13.159.254157.13.159.2554,094
219157.13.160.0/20157.13.160.1 to 157.13.175.254157.13.175.2554,094
220157.13.176.0/20157.13.176.1 to 157.13.191.254157.13.191.2554,094
221157.13.192.0/20157.13.192.1 to 157.13.207.254157.13.207.2554,094
222157.13.208.0/20157.13.208.1 to 157.13.223.254157.13.223.2554,094
223157.13.224.0/20157.13.224.1 to 157.13.239.254157.13.239.2554,094
224157.13.240.0/20157.13.240.1 to 157.13.255.254157.13.255.2554,094
225157.14.0.0/20157.14.0.1 to 157.14.15.254157.14.15.2554,094
226157.14.16.0/20157.14.16.1 to 157.14.31.254157.14.31.2554,094
227157.14.32.0/20157.14.32.1 to 157.14.47.254157.14.47.2554,094
228157.14.48.0/20157.14.48.1 to 157.14.63.254157.14.63.2554,094
229157.14.64.0/20157.14.64.1 to 157.14.79.254157.14.79.2554,094
230157.14.80.0/20157.14.80.1 to 157.14.95.254157.14.95.2554,094
231157.14.96.0/20157.14.96.1 to 157.14.111.254157.14.111.2554,094
232157.14.112.0/20157.14.112.1 to 157.14.127.254157.14.127.2554,094
233157.14.128.0/20157.14.128.1 to 157.14.143.254157.14.143.2554,094
234157.14.144.0/20157.14.144.1 to 157.14.159.254157.14.159.2554,094
235157.14.160.0/20157.14.160.1 to 157.14.175.254157.14.175.2554,094
236157.14.176.0/20157.14.176.1 to 157.14.191.254157.14.191.2554,094
237157.14.192.0/20157.14.192.1 to 157.14.207.254157.14.207.2554,094
238157.14.208.0/20157.14.208.1 to 157.14.223.254157.14.223.2554,094
239157.14.224.0/20157.14.224.1 to 157.14.239.254157.14.239.2554,094
240157.14.240.0/20157.14.240.1 to 157.14.255.254157.14.255.2554,094
241157.15.0.0/20157.15.0.1 to 157.15.15.254157.15.15.2554,094
242157.15.16.0/20157.15.16.1 to 157.15.31.254157.15.31.2554,094
243157.15.32.0/20157.15.32.1 to 157.15.47.254157.15.47.2554,094
244157.15.48.0/20157.15.48.1 to 157.15.63.254157.15.63.2554,094
245157.15.64.0/20157.15.64.1 to 157.15.79.254157.15.79.2554,094
246157.15.80.0/20157.15.80.1 to 157.15.95.254157.15.95.2554,094
247157.15.96.0/20157.15.96.1 to 157.15.111.254157.15.111.2554,094
248157.15.112.0/20157.15.112.1 to 157.15.127.254157.15.127.2554,094
249157.15.128.0/20157.15.128.1 to 157.15.143.254157.15.143.2554,094
250157.15.144.0/20157.15.144.1 to 157.15.159.254157.15.159.2554,094
251157.15.160.0/20157.15.160.1 to 157.15.175.254157.15.175.2554,094
252157.15.176.0/20157.15.176.1 to 157.15.191.254157.15.191.2554,094
253157.15.192.0/20157.15.192.1 to 157.15.207.254157.15.207.2554,094
254157.15.208.0/20157.15.208.1 to 157.15.223.254157.15.223.2554,094
255157.15.224.0/20157.15.224.1 to 157.15.239.254157.15.239.2554,094
256157.15.240.0/20157.15.240.1 to 157.15.255.254157.15.255.2554,094

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.