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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.

Network161.72.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
161.72.0.0
Broadcast address
161.79.255.255
First usable
161.72.0.1
Last usable
161.79.255.254
Usable hosts
524,286 (524,288 less the network and broadcast addresses)
Subnet mask
255.248.0.0
Wildcard mask
0.7.255.255 (Cisco ACLs, OSPF)
Prefix length
/13
Type
Public public
Old class
B (default /16)
As numbers
Hex A1480000 · Integer 2705850368 to 2706374655
Reverse DNS zones
72.161.in-addr.arpa
73.161.in-addr.arpa
74.161.in-addr.arpa
75.161.in-addr.arpa
76.161.in-addr.arpa
77.161.in-addr.arpa
78.161.in-addr.arpa
79.161.in-addr.arpa
/13 is not on a 8-bit boundary, so it takes 8 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10100001.01001000.00000000.00000000161.72.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network10100001.01001000.00000000.00000000161.72.0.0
Broadcast10100001.01001111.11111111.11111111161.79.255.255
Split into smaller subnets/22
/14 (2)/15 (4)/16 (8)/17 (16)/18 (32)/19 (64)/20 (128)/21 (256)/22 (512)/23 (1,024)/24 (2,048)/25 (4,096)

161.72.0.0/13 makes 512 subnets of /22; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1161.72.0.0/22161.72.0.1 to 161.72.3.254161.72.3.2551,022
2161.72.4.0/22161.72.4.1 to 161.72.7.254161.72.7.2551,022
3161.72.8.0/22161.72.8.1 to 161.72.11.254161.72.11.2551,022
4161.72.12.0/22161.72.12.1 to 161.72.15.254161.72.15.2551,022
5161.72.16.0/22161.72.16.1 to 161.72.19.254161.72.19.2551,022
6161.72.20.0/22161.72.20.1 to 161.72.23.254161.72.23.2551,022
7161.72.24.0/22161.72.24.1 to 161.72.27.254161.72.27.2551,022
8161.72.28.0/22161.72.28.1 to 161.72.31.254161.72.31.2551,022
9161.72.32.0/22161.72.32.1 to 161.72.35.254161.72.35.2551,022
10161.72.36.0/22161.72.36.1 to 161.72.39.254161.72.39.2551,022
11161.72.40.0/22161.72.40.1 to 161.72.43.254161.72.43.2551,022
12161.72.44.0/22161.72.44.1 to 161.72.47.254161.72.47.2551,022
13161.72.48.0/22161.72.48.1 to 161.72.51.254161.72.51.2551,022
14161.72.52.0/22161.72.52.1 to 161.72.55.254161.72.55.2551,022
15161.72.56.0/22161.72.56.1 to 161.72.59.254161.72.59.2551,022
16161.72.60.0/22161.72.60.1 to 161.72.63.254161.72.63.2551,022
17161.72.64.0/22161.72.64.1 to 161.72.67.254161.72.67.2551,022
18161.72.68.0/22161.72.68.1 to 161.72.71.254161.72.71.2551,022
19161.72.72.0/22161.72.72.1 to 161.72.75.254161.72.75.2551,022
20161.72.76.0/22161.72.76.1 to 161.72.79.254161.72.79.2551,022
21161.72.80.0/22161.72.80.1 to 161.72.83.254161.72.83.2551,022
22161.72.84.0/22161.72.84.1 to 161.72.87.254161.72.87.2551,022
23161.72.88.0/22161.72.88.1 to 161.72.91.254161.72.91.2551,022
24161.72.92.0/22161.72.92.1 to 161.72.95.254161.72.95.2551,022
25161.72.96.0/22161.72.96.1 to 161.72.99.254161.72.99.2551,022
26161.72.100.0/22161.72.100.1 to 161.72.103.254161.72.103.2551,022
27161.72.104.0/22161.72.104.1 to 161.72.107.254161.72.107.2551,022
28161.72.108.0/22161.72.108.1 to 161.72.111.254161.72.111.2551,022
29161.72.112.0/22161.72.112.1 to 161.72.115.254161.72.115.2551,022
30161.72.116.0/22161.72.116.1 to 161.72.119.254161.72.119.2551,022
31161.72.120.0/22161.72.120.1 to 161.72.123.254161.72.123.2551,022
32161.72.124.0/22161.72.124.1 to 161.72.127.254161.72.127.2551,022
33161.72.128.0/22161.72.128.1 to 161.72.131.254161.72.131.2551,022
34161.72.132.0/22161.72.132.1 to 161.72.135.254161.72.135.2551,022
35161.72.136.0/22161.72.136.1 to 161.72.139.254161.72.139.2551,022
36161.72.140.0/22161.72.140.1 to 161.72.143.254161.72.143.2551,022
37161.72.144.0/22161.72.144.1 to 161.72.147.254161.72.147.2551,022
38161.72.148.0/22161.72.148.1 to 161.72.151.254161.72.151.2551,022
39161.72.152.0/22161.72.152.1 to 161.72.155.254161.72.155.2551,022
40161.72.156.0/22161.72.156.1 to 161.72.159.254161.72.159.2551,022
41161.72.160.0/22161.72.160.1 to 161.72.163.254161.72.163.2551,022
42161.72.164.0/22161.72.164.1 to 161.72.167.254161.72.167.2551,022
43161.72.168.0/22161.72.168.1 to 161.72.171.254161.72.171.2551,022
44161.72.172.0/22161.72.172.1 to 161.72.175.254161.72.175.2551,022
45161.72.176.0/22161.72.176.1 to 161.72.179.254161.72.179.2551,022
46161.72.180.0/22161.72.180.1 to 161.72.183.254161.72.183.2551,022
47161.72.184.0/22161.72.184.1 to 161.72.187.254161.72.187.2551,022
48161.72.188.0/22161.72.188.1 to 161.72.191.254161.72.191.2551,022
49161.72.192.0/22161.72.192.1 to 161.72.195.254161.72.195.2551,022
50161.72.196.0/22161.72.196.1 to 161.72.199.254161.72.199.2551,022
51161.72.200.0/22161.72.200.1 to 161.72.203.254161.72.203.2551,022
52161.72.204.0/22161.72.204.1 to 161.72.207.254161.72.207.2551,022
53161.72.208.0/22161.72.208.1 to 161.72.211.254161.72.211.2551,022
54161.72.212.0/22161.72.212.1 to 161.72.215.254161.72.215.2551,022
55161.72.216.0/22161.72.216.1 to 161.72.219.254161.72.219.2551,022
56161.72.220.0/22161.72.220.1 to 161.72.223.254161.72.223.2551,022
57161.72.224.0/22161.72.224.1 to 161.72.227.254161.72.227.2551,022
58161.72.228.0/22161.72.228.1 to 161.72.231.254161.72.231.2551,022
59161.72.232.0/22161.72.232.1 to 161.72.235.254161.72.235.2551,022
60161.72.236.0/22161.72.236.1 to 161.72.239.254161.72.239.2551,022
61161.72.240.0/22161.72.240.1 to 161.72.243.254161.72.243.2551,022
62161.72.244.0/22161.72.244.1 to 161.72.247.254161.72.247.2551,022
63161.72.248.0/22161.72.248.1 to 161.72.251.254161.72.251.2551,022
64161.72.252.0/22161.72.252.1 to 161.72.255.254161.72.255.2551,022
65161.73.0.0/22161.73.0.1 to 161.73.3.254161.73.3.2551,022
66161.73.4.0/22161.73.4.1 to 161.73.7.254161.73.7.2551,022
67161.73.8.0/22161.73.8.1 to 161.73.11.254161.73.11.2551,022
68161.73.12.0/22161.73.12.1 to 161.73.15.254161.73.15.2551,022
69161.73.16.0/22161.73.16.1 to 161.73.19.254161.73.19.2551,022
70161.73.20.0/22161.73.20.1 to 161.73.23.254161.73.23.2551,022
71161.73.24.0/22161.73.24.1 to 161.73.27.254161.73.27.2551,022
72161.73.28.0/22161.73.28.1 to 161.73.31.254161.73.31.2551,022
73161.73.32.0/22161.73.32.1 to 161.73.35.254161.73.35.2551,022
74161.73.36.0/22161.73.36.1 to 161.73.39.254161.73.39.2551,022
75161.73.40.0/22161.73.40.1 to 161.73.43.254161.73.43.2551,022
76161.73.44.0/22161.73.44.1 to 161.73.47.254161.73.47.2551,022
77161.73.48.0/22161.73.48.1 to 161.73.51.254161.73.51.2551,022
78161.73.52.0/22161.73.52.1 to 161.73.55.254161.73.55.2551,022
79161.73.56.0/22161.73.56.1 to 161.73.59.254161.73.59.2551,022
80161.73.60.0/22161.73.60.1 to 161.73.63.254161.73.63.2551,022
81161.73.64.0/22161.73.64.1 to 161.73.67.254161.73.67.2551,022
82161.73.68.0/22161.73.68.1 to 161.73.71.254161.73.71.2551,022
83161.73.72.0/22161.73.72.1 to 161.73.75.254161.73.75.2551,022
84161.73.76.0/22161.73.76.1 to 161.73.79.254161.73.79.2551,022
85161.73.80.0/22161.73.80.1 to 161.73.83.254161.73.83.2551,022
86161.73.84.0/22161.73.84.1 to 161.73.87.254161.73.87.2551,022
87161.73.88.0/22161.73.88.1 to 161.73.91.254161.73.91.2551,022
88161.73.92.0/22161.73.92.1 to 161.73.95.254161.73.95.2551,022
89161.73.96.0/22161.73.96.1 to 161.73.99.254161.73.99.2551,022
90161.73.100.0/22161.73.100.1 to 161.73.103.254161.73.103.2551,022
91161.73.104.0/22161.73.104.1 to 161.73.107.254161.73.107.2551,022
92161.73.108.0/22161.73.108.1 to 161.73.111.254161.73.111.2551,022
93161.73.112.0/22161.73.112.1 to 161.73.115.254161.73.115.2551,022
94161.73.116.0/22161.73.116.1 to 161.73.119.254161.73.119.2551,022
95161.73.120.0/22161.73.120.1 to 161.73.123.254161.73.123.2551,022
96161.73.124.0/22161.73.124.1 to 161.73.127.254161.73.127.2551,022
97161.73.128.0/22161.73.128.1 to 161.73.131.254161.73.131.2551,022
98161.73.132.0/22161.73.132.1 to 161.73.135.254161.73.135.2551,022
99161.73.136.0/22161.73.136.1 to 161.73.139.254161.73.139.2551,022
100161.73.140.0/22161.73.140.1 to 161.73.143.254161.73.143.2551,022
101161.73.144.0/22161.73.144.1 to 161.73.147.254161.73.147.2551,022
102161.73.148.0/22161.73.148.1 to 161.73.151.254161.73.151.2551,022
103161.73.152.0/22161.73.152.1 to 161.73.155.254161.73.155.2551,022
104161.73.156.0/22161.73.156.1 to 161.73.159.254161.73.159.2551,022
105161.73.160.0/22161.73.160.1 to 161.73.163.254161.73.163.2551,022
106161.73.164.0/22161.73.164.1 to 161.73.167.254161.73.167.2551,022
107161.73.168.0/22161.73.168.1 to 161.73.171.254161.73.171.2551,022
108161.73.172.0/22161.73.172.1 to 161.73.175.254161.73.175.2551,022
109161.73.176.0/22161.73.176.1 to 161.73.179.254161.73.179.2551,022
110161.73.180.0/22161.73.180.1 to 161.73.183.254161.73.183.2551,022
111161.73.184.0/22161.73.184.1 to 161.73.187.254161.73.187.2551,022
112161.73.188.0/22161.73.188.1 to 161.73.191.254161.73.191.2551,022
113161.73.192.0/22161.73.192.1 to 161.73.195.254161.73.195.2551,022
114161.73.196.0/22161.73.196.1 to 161.73.199.254161.73.199.2551,022
115161.73.200.0/22161.73.200.1 to 161.73.203.254161.73.203.2551,022
116161.73.204.0/22161.73.204.1 to 161.73.207.254161.73.207.2551,022
117161.73.208.0/22161.73.208.1 to 161.73.211.254161.73.211.2551,022
118161.73.212.0/22161.73.212.1 to 161.73.215.254161.73.215.2551,022
119161.73.216.0/22161.73.216.1 to 161.73.219.254161.73.219.2551,022
120161.73.220.0/22161.73.220.1 to 161.73.223.254161.73.223.2551,022
121161.73.224.0/22161.73.224.1 to 161.73.227.254161.73.227.2551,022
122161.73.228.0/22161.73.228.1 to 161.73.231.254161.73.231.2551,022
123161.73.232.0/22161.73.232.1 to 161.73.235.254161.73.235.2551,022
124161.73.236.0/22161.73.236.1 to 161.73.239.254161.73.239.2551,022
125161.73.240.0/22161.73.240.1 to 161.73.243.254161.73.243.2551,022
126161.73.244.0/22161.73.244.1 to 161.73.247.254161.73.247.2551,022
127161.73.248.0/22161.73.248.1 to 161.73.251.254161.73.251.2551,022
128161.73.252.0/22161.73.252.1 to 161.73.255.254161.73.255.2551,022
129161.74.0.0/22161.74.0.1 to 161.74.3.254161.74.3.2551,022
130161.74.4.0/22161.74.4.1 to 161.74.7.254161.74.7.2551,022
131161.74.8.0/22161.74.8.1 to 161.74.11.254161.74.11.2551,022
132161.74.12.0/22161.74.12.1 to 161.74.15.254161.74.15.2551,022
133161.74.16.0/22161.74.16.1 to 161.74.19.254161.74.19.2551,022
134161.74.20.0/22161.74.20.1 to 161.74.23.254161.74.23.2551,022
135161.74.24.0/22161.74.24.1 to 161.74.27.254161.74.27.2551,022
136161.74.28.0/22161.74.28.1 to 161.74.31.254161.74.31.2551,022
137161.74.32.0/22161.74.32.1 to 161.74.35.254161.74.35.2551,022
138161.74.36.0/22161.74.36.1 to 161.74.39.254161.74.39.2551,022
139161.74.40.0/22161.74.40.1 to 161.74.43.254161.74.43.2551,022
140161.74.44.0/22161.74.44.1 to 161.74.47.254161.74.47.2551,022
141161.74.48.0/22161.74.48.1 to 161.74.51.254161.74.51.2551,022
142161.74.52.0/22161.74.52.1 to 161.74.55.254161.74.55.2551,022
143161.74.56.0/22161.74.56.1 to 161.74.59.254161.74.59.2551,022
144161.74.60.0/22161.74.60.1 to 161.74.63.254161.74.63.2551,022
145161.74.64.0/22161.74.64.1 to 161.74.67.254161.74.67.2551,022
146161.74.68.0/22161.74.68.1 to 161.74.71.254161.74.71.2551,022
147161.74.72.0/22161.74.72.1 to 161.74.75.254161.74.75.2551,022
148161.74.76.0/22161.74.76.1 to 161.74.79.254161.74.79.2551,022
149161.74.80.0/22161.74.80.1 to 161.74.83.254161.74.83.2551,022
150161.74.84.0/22161.74.84.1 to 161.74.87.254161.74.87.2551,022
151161.74.88.0/22161.74.88.1 to 161.74.91.254161.74.91.2551,022
152161.74.92.0/22161.74.92.1 to 161.74.95.254161.74.95.2551,022
153161.74.96.0/22161.74.96.1 to 161.74.99.254161.74.99.2551,022
154161.74.100.0/22161.74.100.1 to 161.74.103.254161.74.103.2551,022
155161.74.104.0/22161.74.104.1 to 161.74.107.254161.74.107.2551,022
156161.74.108.0/22161.74.108.1 to 161.74.111.254161.74.111.2551,022
157161.74.112.0/22161.74.112.1 to 161.74.115.254161.74.115.2551,022
158161.74.116.0/22161.74.116.1 to 161.74.119.254161.74.119.2551,022
159161.74.120.0/22161.74.120.1 to 161.74.123.254161.74.123.2551,022
160161.74.124.0/22161.74.124.1 to 161.74.127.254161.74.127.2551,022
161161.74.128.0/22161.74.128.1 to 161.74.131.254161.74.131.2551,022
162161.74.132.0/22161.74.132.1 to 161.74.135.254161.74.135.2551,022
163161.74.136.0/22161.74.136.1 to 161.74.139.254161.74.139.2551,022
164161.74.140.0/22161.74.140.1 to 161.74.143.254161.74.143.2551,022
165161.74.144.0/22161.74.144.1 to 161.74.147.254161.74.147.2551,022
166161.74.148.0/22161.74.148.1 to 161.74.151.254161.74.151.2551,022
167161.74.152.0/22161.74.152.1 to 161.74.155.254161.74.155.2551,022
168161.74.156.0/22161.74.156.1 to 161.74.159.254161.74.159.2551,022
169161.74.160.0/22161.74.160.1 to 161.74.163.254161.74.163.2551,022
170161.74.164.0/22161.74.164.1 to 161.74.167.254161.74.167.2551,022
171161.74.168.0/22161.74.168.1 to 161.74.171.254161.74.171.2551,022
172161.74.172.0/22161.74.172.1 to 161.74.175.254161.74.175.2551,022
173161.74.176.0/22161.74.176.1 to 161.74.179.254161.74.179.2551,022
174161.74.180.0/22161.74.180.1 to 161.74.183.254161.74.183.2551,022
175161.74.184.0/22161.74.184.1 to 161.74.187.254161.74.187.2551,022
176161.74.188.0/22161.74.188.1 to 161.74.191.254161.74.191.2551,022
177161.74.192.0/22161.74.192.1 to 161.74.195.254161.74.195.2551,022
178161.74.196.0/22161.74.196.1 to 161.74.199.254161.74.199.2551,022
179161.74.200.0/22161.74.200.1 to 161.74.203.254161.74.203.2551,022
180161.74.204.0/22161.74.204.1 to 161.74.207.254161.74.207.2551,022
181161.74.208.0/22161.74.208.1 to 161.74.211.254161.74.211.2551,022
182161.74.212.0/22161.74.212.1 to 161.74.215.254161.74.215.2551,022
183161.74.216.0/22161.74.216.1 to 161.74.219.254161.74.219.2551,022
184161.74.220.0/22161.74.220.1 to 161.74.223.254161.74.223.2551,022
185161.74.224.0/22161.74.224.1 to 161.74.227.254161.74.227.2551,022
186161.74.228.0/22161.74.228.1 to 161.74.231.254161.74.231.2551,022
187161.74.232.0/22161.74.232.1 to 161.74.235.254161.74.235.2551,022
188161.74.236.0/22161.74.236.1 to 161.74.239.254161.74.239.2551,022
189161.74.240.0/22161.74.240.1 to 161.74.243.254161.74.243.2551,022
190161.74.244.0/22161.74.244.1 to 161.74.247.254161.74.247.2551,022
191161.74.248.0/22161.74.248.1 to 161.74.251.254161.74.251.2551,022
192161.74.252.0/22161.74.252.1 to 161.74.255.254161.74.255.2551,022
193161.75.0.0/22161.75.0.1 to 161.75.3.254161.75.3.2551,022
194161.75.4.0/22161.75.4.1 to 161.75.7.254161.75.7.2551,022
195161.75.8.0/22161.75.8.1 to 161.75.11.254161.75.11.2551,022
196161.75.12.0/22161.75.12.1 to 161.75.15.254161.75.15.2551,022
197161.75.16.0/22161.75.16.1 to 161.75.19.254161.75.19.2551,022
198161.75.20.0/22161.75.20.1 to 161.75.23.254161.75.23.2551,022
199161.75.24.0/22161.75.24.1 to 161.75.27.254161.75.27.2551,022
200161.75.28.0/22161.75.28.1 to 161.75.31.254161.75.31.2551,022
201161.75.32.0/22161.75.32.1 to 161.75.35.254161.75.35.2551,022
202161.75.36.0/22161.75.36.1 to 161.75.39.254161.75.39.2551,022
203161.75.40.0/22161.75.40.1 to 161.75.43.254161.75.43.2551,022
204161.75.44.0/22161.75.44.1 to 161.75.47.254161.75.47.2551,022
205161.75.48.0/22161.75.48.1 to 161.75.51.254161.75.51.2551,022
206161.75.52.0/22161.75.52.1 to 161.75.55.254161.75.55.2551,022
207161.75.56.0/22161.75.56.1 to 161.75.59.254161.75.59.2551,022
208161.75.60.0/22161.75.60.1 to 161.75.63.254161.75.63.2551,022
209161.75.64.0/22161.75.64.1 to 161.75.67.254161.75.67.2551,022
210161.75.68.0/22161.75.68.1 to 161.75.71.254161.75.71.2551,022
211161.75.72.0/22161.75.72.1 to 161.75.75.254161.75.75.2551,022
212161.75.76.0/22161.75.76.1 to 161.75.79.254161.75.79.2551,022
213161.75.80.0/22161.75.80.1 to 161.75.83.254161.75.83.2551,022
214161.75.84.0/22161.75.84.1 to 161.75.87.254161.75.87.2551,022
215161.75.88.0/22161.75.88.1 to 161.75.91.254161.75.91.2551,022
216161.75.92.0/22161.75.92.1 to 161.75.95.254161.75.95.2551,022
217161.75.96.0/22161.75.96.1 to 161.75.99.254161.75.99.2551,022
218161.75.100.0/22161.75.100.1 to 161.75.103.254161.75.103.2551,022
219161.75.104.0/22161.75.104.1 to 161.75.107.254161.75.107.2551,022
220161.75.108.0/22161.75.108.1 to 161.75.111.254161.75.111.2551,022
221161.75.112.0/22161.75.112.1 to 161.75.115.254161.75.115.2551,022
222161.75.116.0/22161.75.116.1 to 161.75.119.254161.75.119.2551,022
223161.75.120.0/22161.75.120.1 to 161.75.123.254161.75.123.2551,022
224161.75.124.0/22161.75.124.1 to 161.75.127.254161.75.127.2551,022
225161.75.128.0/22161.75.128.1 to 161.75.131.254161.75.131.2551,022
226161.75.132.0/22161.75.132.1 to 161.75.135.254161.75.135.2551,022
227161.75.136.0/22161.75.136.1 to 161.75.139.254161.75.139.2551,022
228161.75.140.0/22161.75.140.1 to 161.75.143.254161.75.143.2551,022
229161.75.144.0/22161.75.144.1 to 161.75.147.254161.75.147.2551,022
230161.75.148.0/22161.75.148.1 to 161.75.151.254161.75.151.2551,022
231161.75.152.0/22161.75.152.1 to 161.75.155.254161.75.155.2551,022
232161.75.156.0/22161.75.156.1 to 161.75.159.254161.75.159.2551,022
233161.75.160.0/22161.75.160.1 to 161.75.163.254161.75.163.2551,022
234161.75.164.0/22161.75.164.1 to 161.75.167.254161.75.167.2551,022
235161.75.168.0/22161.75.168.1 to 161.75.171.254161.75.171.2551,022
236161.75.172.0/22161.75.172.1 to 161.75.175.254161.75.175.2551,022
237161.75.176.0/22161.75.176.1 to 161.75.179.254161.75.179.2551,022
238161.75.180.0/22161.75.180.1 to 161.75.183.254161.75.183.2551,022
239161.75.184.0/22161.75.184.1 to 161.75.187.254161.75.187.2551,022
240161.75.188.0/22161.75.188.1 to 161.75.191.254161.75.191.2551,022
241161.75.192.0/22161.75.192.1 to 161.75.195.254161.75.195.2551,022
242161.75.196.0/22161.75.196.1 to 161.75.199.254161.75.199.2551,022
243161.75.200.0/22161.75.200.1 to 161.75.203.254161.75.203.2551,022
244161.75.204.0/22161.75.204.1 to 161.75.207.254161.75.207.2551,022
245161.75.208.0/22161.75.208.1 to 161.75.211.254161.75.211.2551,022
246161.75.212.0/22161.75.212.1 to 161.75.215.254161.75.215.2551,022
247161.75.216.0/22161.75.216.1 to 161.75.219.254161.75.219.2551,022
248161.75.220.0/22161.75.220.1 to 161.75.223.254161.75.223.2551,022
249161.75.224.0/22161.75.224.1 to 161.75.227.254161.75.227.2551,022
250161.75.228.0/22161.75.228.1 to 161.75.231.254161.75.231.2551,022
251161.75.232.0/22161.75.232.1 to 161.75.235.254161.75.235.2551,022
252161.75.236.0/22161.75.236.1 to 161.75.239.254161.75.239.2551,022
253161.75.240.0/22161.75.240.1 to 161.75.243.254161.75.243.2551,022
254161.75.244.0/22161.75.244.1 to 161.75.247.254161.75.247.2551,022
255161.75.248.0/22161.75.248.1 to 161.75.251.254161.75.251.2551,022
256161.75.252.0/22161.75.252.1 to 161.75.255.254161.75.255.2551,022

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.