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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/23
/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 4,096 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1157.0.0.0/23157.0.0.1 to 157.0.1.254157.0.1.255510
2157.0.2.0/23157.0.2.1 to 157.0.3.254157.0.3.255510
3157.0.4.0/23157.0.4.1 to 157.0.5.254157.0.5.255510
4157.0.6.0/23157.0.6.1 to 157.0.7.254157.0.7.255510
5157.0.8.0/23157.0.8.1 to 157.0.9.254157.0.9.255510
6157.0.10.0/23157.0.10.1 to 157.0.11.254157.0.11.255510
7157.0.12.0/23157.0.12.1 to 157.0.13.254157.0.13.255510
8157.0.14.0/23157.0.14.1 to 157.0.15.254157.0.15.255510
9157.0.16.0/23157.0.16.1 to 157.0.17.254157.0.17.255510
10157.0.18.0/23157.0.18.1 to 157.0.19.254157.0.19.255510
11157.0.20.0/23157.0.20.1 to 157.0.21.254157.0.21.255510
12157.0.22.0/23157.0.22.1 to 157.0.23.254157.0.23.255510
13157.0.24.0/23157.0.24.1 to 157.0.25.254157.0.25.255510
14157.0.26.0/23157.0.26.1 to 157.0.27.254157.0.27.255510
15157.0.28.0/23157.0.28.1 to 157.0.29.254157.0.29.255510
16157.0.30.0/23157.0.30.1 to 157.0.31.254157.0.31.255510
17157.0.32.0/23157.0.32.1 to 157.0.33.254157.0.33.255510
18157.0.34.0/23157.0.34.1 to 157.0.35.254157.0.35.255510
19157.0.36.0/23157.0.36.1 to 157.0.37.254157.0.37.255510
20157.0.38.0/23157.0.38.1 to 157.0.39.254157.0.39.255510
21157.0.40.0/23157.0.40.1 to 157.0.41.254157.0.41.255510
22157.0.42.0/23157.0.42.1 to 157.0.43.254157.0.43.255510
23157.0.44.0/23157.0.44.1 to 157.0.45.254157.0.45.255510
24157.0.46.0/23157.0.46.1 to 157.0.47.254157.0.47.255510
25157.0.48.0/23157.0.48.1 to 157.0.49.254157.0.49.255510
26157.0.50.0/23157.0.50.1 to 157.0.51.254157.0.51.255510
27157.0.52.0/23157.0.52.1 to 157.0.53.254157.0.53.255510
28157.0.54.0/23157.0.54.1 to 157.0.55.254157.0.55.255510
29157.0.56.0/23157.0.56.1 to 157.0.57.254157.0.57.255510
30157.0.58.0/23157.0.58.1 to 157.0.59.254157.0.59.255510
31157.0.60.0/23157.0.60.1 to 157.0.61.254157.0.61.255510
32157.0.62.0/23157.0.62.1 to 157.0.63.254157.0.63.255510
33157.0.64.0/23157.0.64.1 to 157.0.65.254157.0.65.255510
34157.0.66.0/23157.0.66.1 to 157.0.67.254157.0.67.255510
35157.0.68.0/23157.0.68.1 to 157.0.69.254157.0.69.255510
36157.0.70.0/23157.0.70.1 to 157.0.71.254157.0.71.255510
37157.0.72.0/23157.0.72.1 to 157.0.73.254157.0.73.255510
38157.0.74.0/23157.0.74.1 to 157.0.75.254157.0.75.255510
39157.0.76.0/23157.0.76.1 to 157.0.77.254157.0.77.255510
40157.0.78.0/23157.0.78.1 to 157.0.79.254157.0.79.255510
41157.0.80.0/23157.0.80.1 to 157.0.81.254157.0.81.255510
42157.0.82.0/23157.0.82.1 to 157.0.83.254157.0.83.255510
43157.0.84.0/23157.0.84.1 to 157.0.85.254157.0.85.255510
44157.0.86.0/23157.0.86.1 to 157.0.87.254157.0.87.255510
45157.0.88.0/23157.0.88.1 to 157.0.89.254157.0.89.255510
46157.0.90.0/23157.0.90.1 to 157.0.91.254157.0.91.255510
47157.0.92.0/23157.0.92.1 to 157.0.93.254157.0.93.255510
48157.0.94.0/23157.0.94.1 to 157.0.95.254157.0.95.255510
49157.0.96.0/23157.0.96.1 to 157.0.97.254157.0.97.255510
50157.0.98.0/23157.0.98.1 to 157.0.99.254157.0.99.255510
51157.0.100.0/23157.0.100.1 to 157.0.101.254157.0.101.255510
52157.0.102.0/23157.0.102.1 to 157.0.103.254157.0.103.255510
53157.0.104.0/23157.0.104.1 to 157.0.105.254157.0.105.255510
54157.0.106.0/23157.0.106.1 to 157.0.107.254157.0.107.255510
55157.0.108.0/23157.0.108.1 to 157.0.109.254157.0.109.255510
56157.0.110.0/23157.0.110.1 to 157.0.111.254157.0.111.255510
57157.0.112.0/23157.0.112.1 to 157.0.113.254157.0.113.255510
58157.0.114.0/23157.0.114.1 to 157.0.115.254157.0.115.255510
59157.0.116.0/23157.0.116.1 to 157.0.117.254157.0.117.255510
60157.0.118.0/23157.0.118.1 to 157.0.119.254157.0.119.255510
61157.0.120.0/23157.0.120.1 to 157.0.121.254157.0.121.255510
62157.0.122.0/23157.0.122.1 to 157.0.123.254157.0.123.255510
63157.0.124.0/23157.0.124.1 to 157.0.125.254157.0.125.255510
64157.0.126.0/23157.0.126.1 to 157.0.127.254157.0.127.255510
65157.0.128.0/23157.0.128.1 to 157.0.129.254157.0.129.255510
66157.0.130.0/23157.0.130.1 to 157.0.131.254157.0.131.255510
67157.0.132.0/23157.0.132.1 to 157.0.133.254157.0.133.255510
68157.0.134.0/23157.0.134.1 to 157.0.135.254157.0.135.255510
69157.0.136.0/23157.0.136.1 to 157.0.137.254157.0.137.255510
70157.0.138.0/23157.0.138.1 to 157.0.139.254157.0.139.255510
71157.0.140.0/23157.0.140.1 to 157.0.141.254157.0.141.255510
72157.0.142.0/23157.0.142.1 to 157.0.143.254157.0.143.255510
73157.0.144.0/23157.0.144.1 to 157.0.145.254157.0.145.255510
74157.0.146.0/23157.0.146.1 to 157.0.147.254157.0.147.255510
75157.0.148.0/23157.0.148.1 to 157.0.149.254157.0.149.255510
76157.0.150.0/23157.0.150.1 to 157.0.151.254157.0.151.255510
77157.0.152.0/23157.0.152.1 to 157.0.153.254157.0.153.255510
78157.0.154.0/23157.0.154.1 to 157.0.155.254157.0.155.255510
79157.0.156.0/23157.0.156.1 to 157.0.157.254157.0.157.255510
80157.0.158.0/23157.0.158.1 to 157.0.159.254157.0.159.255510
81157.0.160.0/23157.0.160.1 to 157.0.161.254157.0.161.255510
82157.0.162.0/23157.0.162.1 to 157.0.163.254157.0.163.255510
83157.0.164.0/23157.0.164.1 to 157.0.165.254157.0.165.255510
84157.0.166.0/23157.0.166.1 to 157.0.167.254157.0.167.255510
85157.0.168.0/23157.0.168.1 to 157.0.169.254157.0.169.255510
86157.0.170.0/23157.0.170.1 to 157.0.171.254157.0.171.255510
87157.0.172.0/23157.0.172.1 to 157.0.173.254157.0.173.255510
88157.0.174.0/23157.0.174.1 to 157.0.175.254157.0.175.255510
89157.0.176.0/23157.0.176.1 to 157.0.177.254157.0.177.255510
90157.0.178.0/23157.0.178.1 to 157.0.179.254157.0.179.255510
91157.0.180.0/23157.0.180.1 to 157.0.181.254157.0.181.255510
92157.0.182.0/23157.0.182.1 to 157.0.183.254157.0.183.255510
93157.0.184.0/23157.0.184.1 to 157.0.185.254157.0.185.255510
94157.0.186.0/23157.0.186.1 to 157.0.187.254157.0.187.255510
95157.0.188.0/23157.0.188.1 to 157.0.189.254157.0.189.255510
96157.0.190.0/23157.0.190.1 to 157.0.191.254157.0.191.255510
97157.0.192.0/23157.0.192.1 to 157.0.193.254157.0.193.255510
98157.0.194.0/23157.0.194.1 to 157.0.195.254157.0.195.255510
99157.0.196.0/23157.0.196.1 to 157.0.197.254157.0.197.255510
100157.0.198.0/23157.0.198.1 to 157.0.199.254157.0.199.255510
101157.0.200.0/23157.0.200.1 to 157.0.201.254157.0.201.255510
102157.0.202.0/23157.0.202.1 to 157.0.203.254157.0.203.255510
103157.0.204.0/23157.0.204.1 to 157.0.205.254157.0.205.255510
104157.0.206.0/23157.0.206.1 to 157.0.207.254157.0.207.255510
105157.0.208.0/23157.0.208.1 to 157.0.209.254157.0.209.255510
106157.0.210.0/23157.0.210.1 to 157.0.211.254157.0.211.255510
107157.0.212.0/23157.0.212.1 to 157.0.213.254157.0.213.255510
108157.0.214.0/23157.0.214.1 to 157.0.215.254157.0.215.255510
109157.0.216.0/23157.0.216.1 to 157.0.217.254157.0.217.255510
110157.0.218.0/23157.0.218.1 to 157.0.219.254157.0.219.255510
111157.0.220.0/23157.0.220.1 to 157.0.221.254157.0.221.255510
112157.0.222.0/23157.0.222.1 to 157.0.223.254157.0.223.255510
113157.0.224.0/23157.0.224.1 to 157.0.225.254157.0.225.255510
114157.0.226.0/23157.0.226.1 to 157.0.227.254157.0.227.255510
115157.0.228.0/23157.0.228.1 to 157.0.229.254157.0.229.255510
116157.0.230.0/23157.0.230.1 to 157.0.231.254157.0.231.255510
117157.0.232.0/23157.0.232.1 to 157.0.233.254157.0.233.255510
118157.0.234.0/23157.0.234.1 to 157.0.235.254157.0.235.255510
119157.0.236.0/23157.0.236.1 to 157.0.237.254157.0.237.255510
120157.0.238.0/23157.0.238.1 to 157.0.239.254157.0.239.255510
121157.0.240.0/23157.0.240.1 to 157.0.241.254157.0.241.255510
122157.0.242.0/23157.0.242.1 to 157.0.243.254157.0.243.255510
123157.0.244.0/23157.0.244.1 to 157.0.245.254157.0.245.255510
124157.0.246.0/23157.0.246.1 to 157.0.247.254157.0.247.255510
125157.0.248.0/23157.0.248.1 to 157.0.249.254157.0.249.255510
126157.0.250.0/23157.0.250.1 to 157.0.251.254157.0.251.255510
127157.0.252.0/23157.0.252.1 to 157.0.253.254157.0.253.255510
128157.0.254.0/23157.0.254.1 to 157.0.255.254157.0.255.255510
129157.1.0.0/23157.1.0.1 to 157.1.1.254157.1.1.255510
130157.1.2.0/23157.1.2.1 to 157.1.3.254157.1.3.255510
131157.1.4.0/23157.1.4.1 to 157.1.5.254157.1.5.255510
132157.1.6.0/23157.1.6.1 to 157.1.7.254157.1.7.255510
133157.1.8.0/23157.1.8.1 to 157.1.9.254157.1.9.255510
134157.1.10.0/23157.1.10.1 to 157.1.11.254157.1.11.255510
135157.1.12.0/23157.1.12.1 to 157.1.13.254157.1.13.255510
136157.1.14.0/23157.1.14.1 to 157.1.15.254157.1.15.255510
137157.1.16.0/23157.1.16.1 to 157.1.17.254157.1.17.255510
138157.1.18.0/23157.1.18.1 to 157.1.19.254157.1.19.255510
139157.1.20.0/23157.1.20.1 to 157.1.21.254157.1.21.255510
140157.1.22.0/23157.1.22.1 to 157.1.23.254157.1.23.255510
141157.1.24.0/23157.1.24.1 to 157.1.25.254157.1.25.255510
142157.1.26.0/23157.1.26.1 to 157.1.27.254157.1.27.255510
143157.1.28.0/23157.1.28.1 to 157.1.29.254157.1.29.255510
144157.1.30.0/23157.1.30.1 to 157.1.31.254157.1.31.255510
145157.1.32.0/23157.1.32.1 to 157.1.33.254157.1.33.255510
146157.1.34.0/23157.1.34.1 to 157.1.35.254157.1.35.255510
147157.1.36.0/23157.1.36.1 to 157.1.37.254157.1.37.255510
148157.1.38.0/23157.1.38.1 to 157.1.39.254157.1.39.255510
149157.1.40.0/23157.1.40.1 to 157.1.41.254157.1.41.255510
150157.1.42.0/23157.1.42.1 to 157.1.43.254157.1.43.255510
151157.1.44.0/23157.1.44.1 to 157.1.45.254157.1.45.255510
152157.1.46.0/23157.1.46.1 to 157.1.47.254157.1.47.255510
153157.1.48.0/23157.1.48.1 to 157.1.49.254157.1.49.255510
154157.1.50.0/23157.1.50.1 to 157.1.51.254157.1.51.255510
155157.1.52.0/23157.1.52.1 to 157.1.53.254157.1.53.255510
156157.1.54.0/23157.1.54.1 to 157.1.55.254157.1.55.255510
157157.1.56.0/23157.1.56.1 to 157.1.57.254157.1.57.255510
158157.1.58.0/23157.1.58.1 to 157.1.59.254157.1.59.255510
159157.1.60.0/23157.1.60.1 to 157.1.61.254157.1.61.255510
160157.1.62.0/23157.1.62.1 to 157.1.63.254157.1.63.255510
161157.1.64.0/23157.1.64.1 to 157.1.65.254157.1.65.255510
162157.1.66.0/23157.1.66.1 to 157.1.67.254157.1.67.255510
163157.1.68.0/23157.1.68.1 to 157.1.69.254157.1.69.255510
164157.1.70.0/23157.1.70.1 to 157.1.71.254157.1.71.255510
165157.1.72.0/23157.1.72.1 to 157.1.73.254157.1.73.255510
166157.1.74.0/23157.1.74.1 to 157.1.75.254157.1.75.255510
167157.1.76.0/23157.1.76.1 to 157.1.77.254157.1.77.255510
168157.1.78.0/23157.1.78.1 to 157.1.79.254157.1.79.255510
169157.1.80.0/23157.1.80.1 to 157.1.81.254157.1.81.255510
170157.1.82.0/23157.1.82.1 to 157.1.83.254157.1.83.255510
171157.1.84.0/23157.1.84.1 to 157.1.85.254157.1.85.255510
172157.1.86.0/23157.1.86.1 to 157.1.87.254157.1.87.255510
173157.1.88.0/23157.1.88.1 to 157.1.89.254157.1.89.255510
174157.1.90.0/23157.1.90.1 to 157.1.91.254157.1.91.255510
175157.1.92.0/23157.1.92.1 to 157.1.93.254157.1.93.255510
176157.1.94.0/23157.1.94.1 to 157.1.95.254157.1.95.255510
177157.1.96.0/23157.1.96.1 to 157.1.97.254157.1.97.255510
178157.1.98.0/23157.1.98.1 to 157.1.99.254157.1.99.255510
179157.1.100.0/23157.1.100.1 to 157.1.101.254157.1.101.255510
180157.1.102.0/23157.1.102.1 to 157.1.103.254157.1.103.255510
181157.1.104.0/23157.1.104.1 to 157.1.105.254157.1.105.255510
182157.1.106.0/23157.1.106.1 to 157.1.107.254157.1.107.255510
183157.1.108.0/23157.1.108.1 to 157.1.109.254157.1.109.255510
184157.1.110.0/23157.1.110.1 to 157.1.111.254157.1.111.255510
185157.1.112.0/23157.1.112.1 to 157.1.113.254157.1.113.255510
186157.1.114.0/23157.1.114.1 to 157.1.115.254157.1.115.255510
187157.1.116.0/23157.1.116.1 to 157.1.117.254157.1.117.255510
188157.1.118.0/23157.1.118.1 to 157.1.119.254157.1.119.255510
189157.1.120.0/23157.1.120.1 to 157.1.121.254157.1.121.255510
190157.1.122.0/23157.1.122.1 to 157.1.123.254157.1.123.255510
191157.1.124.0/23157.1.124.1 to 157.1.125.254157.1.125.255510
192157.1.126.0/23157.1.126.1 to 157.1.127.254157.1.127.255510
193157.1.128.0/23157.1.128.1 to 157.1.129.254157.1.129.255510
194157.1.130.0/23157.1.130.1 to 157.1.131.254157.1.131.255510
195157.1.132.0/23157.1.132.1 to 157.1.133.254157.1.133.255510
196157.1.134.0/23157.1.134.1 to 157.1.135.254157.1.135.255510
197157.1.136.0/23157.1.136.1 to 157.1.137.254157.1.137.255510
198157.1.138.0/23157.1.138.1 to 157.1.139.254157.1.139.255510
199157.1.140.0/23157.1.140.1 to 157.1.141.254157.1.141.255510
200157.1.142.0/23157.1.142.1 to 157.1.143.254157.1.143.255510
201157.1.144.0/23157.1.144.1 to 157.1.145.254157.1.145.255510
202157.1.146.0/23157.1.146.1 to 157.1.147.254157.1.147.255510
203157.1.148.0/23157.1.148.1 to 157.1.149.254157.1.149.255510
204157.1.150.0/23157.1.150.1 to 157.1.151.254157.1.151.255510
205157.1.152.0/23157.1.152.1 to 157.1.153.254157.1.153.255510
206157.1.154.0/23157.1.154.1 to 157.1.155.254157.1.155.255510
207157.1.156.0/23157.1.156.1 to 157.1.157.254157.1.157.255510
208157.1.158.0/23157.1.158.1 to 157.1.159.254157.1.159.255510
209157.1.160.0/23157.1.160.1 to 157.1.161.254157.1.161.255510
210157.1.162.0/23157.1.162.1 to 157.1.163.254157.1.163.255510
211157.1.164.0/23157.1.164.1 to 157.1.165.254157.1.165.255510
212157.1.166.0/23157.1.166.1 to 157.1.167.254157.1.167.255510
213157.1.168.0/23157.1.168.1 to 157.1.169.254157.1.169.255510
214157.1.170.0/23157.1.170.1 to 157.1.171.254157.1.171.255510
215157.1.172.0/23157.1.172.1 to 157.1.173.254157.1.173.255510
216157.1.174.0/23157.1.174.1 to 157.1.175.254157.1.175.255510
217157.1.176.0/23157.1.176.1 to 157.1.177.254157.1.177.255510
218157.1.178.0/23157.1.178.1 to 157.1.179.254157.1.179.255510
219157.1.180.0/23157.1.180.1 to 157.1.181.254157.1.181.255510
220157.1.182.0/23157.1.182.1 to 157.1.183.254157.1.183.255510
221157.1.184.0/23157.1.184.1 to 157.1.185.254157.1.185.255510
222157.1.186.0/23157.1.186.1 to 157.1.187.254157.1.187.255510
223157.1.188.0/23157.1.188.1 to 157.1.189.254157.1.189.255510
224157.1.190.0/23157.1.190.1 to 157.1.191.254157.1.191.255510
225157.1.192.0/23157.1.192.1 to 157.1.193.254157.1.193.255510
226157.1.194.0/23157.1.194.1 to 157.1.195.254157.1.195.255510
227157.1.196.0/23157.1.196.1 to 157.1.197.254157.1.197.255510
228157.1.198.0/23157.1.198.1 to 157.1.199.254157.1.199.255510
229157.1.200.0/23157.1.200.1 to 157.1.201.254157.1.201.255510
230157.1.202.0/23157.1.202.1 to 157.1.203.254157.1.203.255510
231157.1.204.0/23157.1.204.1 to 157.1.205.254157.1.205.255510
232157.1.206.0/23157.1.206.1 to 157.1.207.254157.1.207.255510
233157.1.208.0/23157.1.208.1 to 157.1.209.254157.1.209.255510
234157.1.210.0/23157.1.210.1 to 157.1.211.254157.1.211.255510
235157.1.212.0/23157.1.212.1 to 157.1.213.254157.1.213.255510
236157.1.214.0/23157.1.214.1 to 157.1.215.254157.1.215.255510
237157.1.216.0/23157.1.216.1 to 157.1.217.254157.1.217.255510
238157.1.218.0/23157.1.218.1 to 157.1.219.254157.1.219.255510
239157.1.220.0/23157.1.220.1 to 157.1.221.254157.1.221.255510
240157.1.222.0/23157.1.222.1 to 157.1.223.254157.1.223.255510
241157.1.224.0/23157.1.224.1 to 157.1.225.254157.1.225.255510
242157.1.226.0/23157.1.226.1 to 157.1.227.254157.1.227.255510
243157.1.228.0/23157.1.228.1 to 157.1.229.254157.1.229.255510
244157.1.230.0/23157.1.230.1 to 157.1.231.254157.1.231.255510
245157.1.232.0/23157.1.232.1 to 157.1.233.254157.1.233.255510
246157.1.234.0/23157.1.234.1 to 157.1.235.254157.1.235.255510
247157.1.236.0/23157.1.236.1 to 157.1.237.254157.1.237.255510
248157.1.238.0/23157.1.238.1 to 157.1.239.254157.1.239.255510
249157.1.240.0/23157.1.240.1 to 157.1.241.254157.1.241.255510
250157.1.242.0/23157.1.242.1 to 157.1.243.254157.1.243.255510
251157.1.244.0/23157.1.244.1 to 157.1.245.254157.1.245.255510
252157.1.246.0/23157.1.246.1 to 157.1.247.254157.1.247.255510
253157.1.248.0/23157.1.248.1 to 157.1.249.254157.1.249.255510
254157.1.250.0/23157.1.250.1 to 157.1.251.254157.1.251.255510
255157.1.252.0/23157.1.252.1 to 157.1.253.254157.1.253.255510
256157.1.254.0/23157.1.254.1 to 157.1.255.254157.1.255.255510

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.