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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.

Network155.232.0.0/13
Usable hosts524,286
Subnet mask255.248.0.0
Addresses524,288
Network address
155.232.0.0
Broadcast address
155.239.255.255
First usable
155.232.0.1
Last usable
155.239.255.254
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 9BE80000 · Integer 2615672832 to 2616197119
Reverse DNS zones
232.155.in-addr.arpa
233.155.in-addr.arpa
234.155.in-addr.arpa
235.155.in-addr.arpa
236.155.in-addr.arpa
237.155.in-addr.arpa
238.155.in-addr.arpa
239.155.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
Address10011011.11101000.00000000.00000000155.232.0.0
Subnet mask11111111.11111000.00000000.00000000255.248.0.0
Network10011011.11101000.00000000.00000000155.232.0.0
Broadcast10011011.11101111.11111111.11111111155.239.255.255
Split into smaller subnets/23
/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)

155.232.0.0/13 makes 1,024 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1155.232.0.0/23155.232.0.1 to 155.232.1.254155.232.1.255510
2155.232.2.0/23155.232.2.1 to 155.232.3.254155.232.3.255510
3155.232.4.0/23155.232.4.1 to 155.232.5.254155.232.5.255510
4155.232.6.0/23155.232.6.1 to 155.232.7.254155.232.7.255510
5155.232.8.0/23155.232.8.1 to 155.232.9.254155.232.9.255510
6155.232.10.0/23155.232.10.1 to 155.232.11.254155.232.11.255510
7155.232.12.0/23155.232.12.1 to 155.232.13.254155.232.13.255510
8155.232.14.0/23155.232.14.1 to 155.232.15.254155.232.15.255510
9155.232.16.0/23155.232.16.1 to 155.232.17.254155.232.17.255510
10155.232.18.0/23155.232.18.1 to 155.232.19.254155.232.19.255510
11155.232.20.0/23155.232.20.1 to 155.232.21.254155.232.21.255510
12155.232.22.0/23155.232.22.1 to 155.232.23.254155.232.23.255510
13155.232.24.0/23155.232.24.1 to 155.232.25.254155.232.25.255510
14155.232.26.0/23155.232.26.1 to 155.232.27.254155.232.27.255510
15155.232.28.0/23155.232.28.1 to 155.232.29.254155.232.29.255510
16155.232.30.0/23155.232.30.1 to 155.232.31.254155.232.31.255510
17155.232.32.0/23155.232.32.1 to 155.232.33.254155.232.33.255510
18155.232.34.0/23155.232.34.1 to 155.232.35.254155.232.35.255510
19155.232.36.0/23155.232.36.1 to 155.232.37.254155.232.37.255510
20155.232.38.0/23155.232.38.1 to 155.232.39.254155.232.39.255510
21155.232.40.0/23155.232.40.1 to 155.232.41.254155.232.41.255510
22155.232.42.0/23155.232.42.1 to 155.232.43.254155.232.43.255510
23155.232.44.0/23155.232.44.1 to 155.232.45.254155.232.45.255510
24155.232.46.0/23155.232.46.1 to 155.232.47.254155.232.47.255510
25155.232.48.0/23155.232.48.1 to 155.232.49.254155.232.49.255510
26155.232.50.0/23155.232.50.1 to 155.232.51.254155.232.51.255510
27155.232.52.0/23155.232.52.1 to 155.232.53.254155.232.53.255510
28155.232.54.0/23155.232.54.1 to 155.232.55.254155.232.55.255510
29155.232.56.0/23155.232.56.1 to 155.232.57.254155.232.57.255510
30155.232.58.0/23155.232.58.1 to 155.232.59.254155.232.59.255510
31155.232.60.0/23155.232.60.1 to 155.232.61.254155.232.61.255510
32155.232.62.0/23155.232.62.1 to 155.232.63.254155.232.63.255510
33155.232.64.0/23155.232.64.1 to 155.232.65.254155.232.65.255510
34155.232.66.0/23155.232.66.1 to 155.232.67.254155.232.67.255510
35155.232.68.0/23155.232.68.1 to 155.232.69.254155.232.69.255510
36155.232.70.0/23155.232.70.1 to 155.232.71.254155.232.71.255510
37155.232.72.0/23155.232.72.1 to 155.232.73.254155.232.73.255510
38155.232.74.0/23155.232.74.1 to 155.232.75.254155.232.75.255510
39155.232.76.0/23155.232.76.1 to 155.232.77.254155.232.77.255510
40155.232.78.0/23155.232.78.1 to 155.232.79.254155.232.79.255510
41155.232.80.0/23155.232.80.1 to 155.232.81.254155.232.81.255510
42155.232.82.0/23155.232.82.1 to 155.232.83.254155.232.83.255510
43155.232.84.0/23155.232.84.1 to 155.232.85.254155.232.85.255510
44155.232.86.0/23155.232.86.1 to 155.232.87.254155.232.87.255510
45155.232.88.0/23155.232.88.1 to 155.232.89.254155.232.89.255510
46155.232.90.0/23155.232.90.1 to 155.232.91.254155.232.91.255510
47155.232.92.0/23155.232.92.1 to 155.232.93.254155.232.93.255510
48155.232.94.0/23155.232.94.1 to 155.232.95.254155.232.95.255510
49155.232.96.0/23155.232.96.1 to 155.232.97.254155.232.97.255510
50155.232.98.0/23155.232.98.1 to 155.232.99.254155.232.99.255510
51155.232.100.0/23155.232.100.1 to 155.232.101.254155.232.101.255510
52155.232.102.0/23155.232.102.1 to 155.232.103.254155.232.103.255510
53155.232.104.0/23155.232.104.1 to 155.232.105.254155.232.105.255510
54155.232.106.0/23155.232.106.1 to 155.232.107.254155.232.107.255510
55155.232.108.0/23155.232.108.1 to 155.232.109.254155.232.109.255510
56155.232.110.0/23155.232.110.1 to 155.232.111.254155.232.111.255510
57155.232.112.0/23155.232.112.1 to 155.232.113.254155.232.113.255510
58155.232.114.0/23155.232.114.1 to 155.232.115.254155.232.115.255510
59155.232.116.0/23155.232.116.1 to 155.232.117.254155.232.117.255510
60155.232.118.0/23155.232.118.1 to 155.232.119.254155.232.119.255510
61155.232.120.0/23155.232.120.1 to 155.232.121.254155.232.121.255510
62155.232.122.0/23155.232.122.1 to 155.232.123.254155.232.123.255510
63155.232.124.0/23155.232.124.1 to 155.232.125.254155.232.125.255510
64155.232.126.0/23155.232.126.1 to 155.232.127.254155.232.127.255510
65155.232.128.0/23155.232.128.1 to 155.232.129.254155.232.129.255510
66155.232.130.0/23155.232.130.1 to 155.232.131.254155.232.131.255510
67155.232.132.0/23155.232.132.1 to 155.232.133.254155.232.133.255510
68155.232.134.0/23155.232.134.1 to 155.232.135.254155.232.135.255510
69155.232.136.0/23155.232.136.1 to 155.232.137.254155.232.137.255510
70155.232.138.0/23155.232.138.1 to 155.232.139.254155.232.139.255510
71155.232.140.0/23155.232.140.1 to 155.232.141.254155.232.141.255510
72155.232.142.0/23155.232.142.1 to 155.232.143.254155.232.143.255510
73155.232.144.0/23155.232.144.1 to 155.232.145.254155.232.145.255510
74155.232.146.0/23155.232.146.1 to 155.232.147.254155.232.147.255510
75155.232.148.0/23155.232.148.1 to 155.232.149.254155.232.149.255510
76155.232.150.0/23155.232.150.1 to 155.232.151.254155.232.151.255510
77155.232.152.0/23155.232.152.1 to 155.232.153.254155.232.153.255510
78155.232.154.0/23155.232.154.1 to 155.232.155.254155.232.155.255510
79155.232.156.0/23155.232.156.1 to 155.232.157.254155.232.157.255510
80155.232.158.0/23155.232.158.1 to 155.232.159.254155.232.159.255510
81155.232.160.0/23155.232.160.1 to 155.232.161.254155.232.161.255510
82155.232.162.0/23155.232.162.1 to 155.232.163.254155.232.163.255510
83155.232.164.0/23155.232.164.1 to 155.232.165.254155.232.165.255510
84155.232.166.0/23155.232.166.1 to 155.232.167.254155.232.167.255510
85155.232.168.0/23155.232.168.1 to 155.232.169.254155.232.169.255510
86155.232.170.0/23155.232.170.1 to 155.232.171.254155.232.171.255510
87155.232.172.0/23155.232.172.1 to 155.232.173.254155.232.173.255510
88155.232.174.0/23155.232.174.1 to 155.232.175.254155.232.175.255510
89155.232.176.0/23155.232.176.1 to 155.232.177.254155.232.177.255510
90155.232.178.0/23155.232.178.1 to 155.232.179.254155.232.179.255510
91155.232.180.0/23155.232.180.1 to 155.232.181.254155.232.181.255510
92155.232.182.0/23155.232.182.1 to 155.232.183.254155.232.183.255510
93155.232.184.0/23155.232.184.1 to 155.232.185.254155.232.185.255510
94155.232.186.0/23155.232.186.1 to 155.232.187.254155.232.187.255510
95155.232.188.0/23155.232.188.1 to 155.232.189.254155.232.189.255510
96155.232.190.0/23155.232.190.1 to 155.232.191.254155.232.191.255510
97155.232.192.0/23155.232.192.1 to 155.232.193.254155.232.193.255510
98155.232.194.0/23155.232.194.1 to 155.232.195.254155.232.195.255510
99155.232.196.0/23155.232.196.1 to 155.232.197.254155.232.197.255510
100155.232.198.0/23155.232.198.1 to 155.232.199.254155.232.199.255510
101155.232.200.0/23155.232.200.1 to 155.232.201.254155.232.201.255510
102155.232.202.0/23155.232.202.1 to 155.232.203.254155.232.203.255510
103155.232.204.0/23155.232.204.1 to 155.232.205.254155.232.205.255510
104155.232.206.0/23155.232.206.1 to 155.232.207.254155.232.207.255510
105155.232.208.0/23155.232.208.1 to 155.232.209.254155.232.209.255510
106155.232.210.0/23155.232.210.1 to 155.232.211.254155.232.211.255510
107155.232.212.0/23155.232.212.1 to 155.232.213.254155.232.213.255510
108155.232.214.0/23155.232.214.1 to 155.232.215.254155.232.215.255510
109155.232.216.0/23155.232.216.1 to 155.232.217.254155.232.217.255510
110155.232.218.0/23155.232.218.1 to 155.232.219.254155.232.219.255510
111155.232.220.0/23155.232.220.1 to 155.232.221.254155.232.221.255510
112155.232.222.0/23155.232.222.1 to 155.232.223.254155.232.223.255510
113155.232.224.0/23155.232.224.1 to 155.232.225.254155.232.225.255510
114155.232.226.0/23155.232.226.1 to 155.232.227.254155.232.227.255510
115155.232.228.0/23155.232.228.1 to 155.232.229.254155.232.229.255510
116155.232.230.0/23155.232.230.1 to 155.232.231.254155.232.231.255510
117155.232.232.0/23155.232.232.1 to 155.232.233.254155.232.233.255510
118155.232.234.0/23155.232.234.1 to 155.232.235.254155.232.235.255510
119155.232.236.0/23155.232.236.1 to 155.232.237.254155.232.237.255510
120155.232.238.0/23155.232.238.1 to 155.232.239.254155.232.239.255510
121155.232.240.0/23155.232.240.1 to 155.232.241.254155.232.241.255510
122155.232.242.0/23155.232.242.1 to 155.232.243.254155.232.243.255510
123155.232.244.0/23155.232.244.1 to 155.232.245.254155.232.245.255510
124155.232.246.0/23155.232.246.1 to 155.232.247.254155.232.247.255510
125155.232.248.0/23155.232.248.1 to 155.232.249.254155.232.249.255510
126155.232.250.0/23155.232.250.1 to 155.232.251.254155.232.251.255510
127155.232.252.0/23155.232.252.1 to 155.232.253.254155.232.253.255510
128155.232.254.0/23155.232.254.1 to 155.232.255.254155.232.255.255510
129155.233.0.0/23155.233.0.1 to 155.233.1.254155.233.1.255510
130155.233.2.0/23155.233.2.1 to 155.233.3.254155.233.3.255510
131155.233.4.0/23155.233.4.1 to 155.233.5.254155.233.5.255510
132155.233.6.0/23155.233.6.1 to 155.233.7.254155.233.7.255510
133155.233.8.0/23155.233.8.1 to 155.233.9.254155.233.9.255510
134155.233.10.0/23155.233.10.1 to 155.233.11.254155.233.11.255510
135155.233.12.0/23155.233.12.1 to 155.233.13.254155.233.13.255510
136155.233.14.0/23155.233.14.1 to 155.233.15.254155.233.15.255510
137155.233.16.0/23155.233.16.1 to 155.233.17.254155.233.17.255510
138155.233.18.0/23155.233.18.1 to 155.233.19.254155.233.19.255510
139155.233.20.0/23155.233.20.1 to 155.233.21.254155.233.21.255510
140155.233.22.0/23155.233.22.1 to 155.233.23.254155.233.23.255510
141155.233.24.0/23155.233.24.1 to 155.233.25.254155.233.25.255510
142155.233.26.0/23155.233.26.1 to 155.233.27.254155.233.27.255510
143155.233.28.0/23155.233.28.1 to 155.233.29.254155.233.29.255510
144155.233.30.0/23155.233.30.1 to 155.233.31.254155.233.31.255510
145155.233.32.0/23155.233.32.1 to 155.233.33.254155.233.33.255510
146155.233.34.0/23155.233.34.1 to 155.233.35.254155.233.35.255510
147155.233.36.0/23155.233.36.1 to 155.233.37.254155.233.37.255510
148155.233.38.0/23155.233.38.1 to 155.233.39.254155.233.39.255510
149155.233.40.0/23155.233.40.1 to 155.233.41.254155.233.41.255510
150155.233.42.0/23155.233.42.1 to 155.233.43.254155.233.43.255510
151155.233.44.0/23155.233.44.1 to 155.233.45.254155.233.45.255510
152155.233.46.0/23155.233.46.1 to 155.233.47.254155.233.47.255510
153155.233.48.0/23155.233.48.1 to 155.233.49.254155.233.49.255510
154155.233.50.0/23155.233.50.1 to 155.233.51.254155.233.51.255510
155155.233.52.0/23155.233.52.1 to 155.233.53.254155.233.53.255510
156155.233.54.0/23155.233.54.1 to 155.233.55.254155.233.55.255510
157155.233.56.0/23155.233.56.1 to 155.233.57.254155.233.57.255510
158155.233.58.0/23155.233.58.1 to 155.233.59.254155.233.59.255510
159155.233.60.0/23155.233.60.1 to 155.233.61.254155.233.61.255510
160155.233.62.0/23155.233.62.1 to 155.233.63.254155.233.63.255510
161155.233.64.0/23155.233.64.1 to 155.233.65.254155.233.65.255510
162155.233.66.0/23155.233.66.1 to 155.233.67.254155.233.67.255510
163155.233.68.0/23155.233.68.1 to 155.233.69.254155.233.69.255510
164155.233.70.0/23155.233.70.1 to 155.233.71.254155.233.71.255510
165155.233.72.0/23155.233.72.1 to 155.233.73.254155.233.73.255510
166155.233.74.0/23155.233.74.1 to 155.233.75.254155.233.75.255510
167155.233.76.0/23155.233.76.1 to 155.233.77.254155.233.77.255510
168155.233.78.0/23155.233.78.1 to 155.233.79.254155.233.79.255510
169155.233.80.0/23155.233.80.1 to 155.233.81.254155.233.81.255510
170155.233.82.0/23155.233.82.1 to 155.233.83.254155.233.83.255510
171155.233.84.0/23155.233.84.1 to 155.233.85.254155.233.85.255510
172155.233.86.0/23155.233.86.1 to 155.233.87.254155.233.87.255510
173155.233.88.0/23155.233.88.1 to 155.233.89.254155.233.89.255510
174155.233.90.0/23155.233.90.1 to 155.233.91.254155.233.91.255510
175155.233.92.0/23155.233.92.1 to 155.233.93.254155.233.93.255510
176155.233.94.0/23155.233.94.1 to 155.233.95.254155.233.95.255510
177155.233.96.0/23155.233.96.1 to 155.233.97.254155.233.97.255510
178155.233.98.0/23155.233.98.1 to 155.233.99.254155.233.99.255510
179155.233.100.0/23155.233.100.1 to 155.233.101.254155.233.101.255510
180155.233.102.0/23155.233.102.1 to 155.233.103.254155.233.103.255510
181155.233.104.0/23155.233.104.1 to 155.233.105.254155.233.105.255510
182155.233.106.0/23155.233.106.1 to 155.233.107.254155.233.107.255510
183155.233.108.0/23155.233.108.1 to 155.233.109.254155.233.109.255510
184155.233.110.0/23155.233.110.1 to 155.233.111.254155.233.111.255510
185155.233.112.0/23155.233.112.1 to 155.233.113.254155.233.113.255510
186155.233.114.0/23155.233.114.1 to 155.233.115.254155.233.115.255510
187155.233.116.0/23155.233.116.1 to 155.233.117.254155.233.117.255510
188155.233.118.0/23155.233.118.1 to 155.233.119.254155.233.119.255510
189155.233.120.0/23155.233.120.1 to 155.233.121.254155.233.121.255510
190155.233.122.0/23155.233.122.1 to 155.233.123.254155.233.123.255510
191155.233.124.0/23155.233.124.1 to 155.233.125.254155.233.125.255510
192155.233.126.0/23155.233.126.1 to 155.233.127.254155.233.127.255510
193155.233.128.0/23155.233.128.1 to 155.233.129.254155.233.129.255510
194155.233.130.0/23155.233.130.1 to 155.233.131.254155.233.131.255510
195155.233.132.0/23155.233.132.1 to 155.233.133.254155.233.133.255510
196155.233.134.0/23155.233.134.1 to 155.233.135.254155.233.135.255510
197155.233.136.0/23155.233.136.1 to 155.233.137.254155.233.137.255510
198155.233.138.0/23155.233.138.1 to 155.233.139.254155.233.139.255510
199155.233.140.0/23155.233.140.1 to 155.233.141.254155.233.141.255510
200155.233.142.0/23155.233.142.1 to 155.233.143.254155.233.143.255510
201155.233.144.0/23155.233.144.1 to 155.233.145.254155.233.145.255510
202155.233.146.0/23155.233.146.1 to 155.233.147.254155.233.147.255510
203155.233.148.0/23155.233.148.1 to 155.233.149.254155.233.149.255510
204155.233.150.0/23155.233.150.1 to 155.233.151.254155.233.151.255510
205155.233.152.0/23155.233.152.1 to 155.233.153.254155.233.153.255510
206155.233.154.0/23155.233.154.1 to 155.233.155.254155.233.155.255510
207155.233.156.0/23155.233.156.1 to 155.233.157.254155.233.157.255510
208155.233.158.0/23155.233.158.1 to 155.233.159.254155.233.159.255510
209155.233.160.0/23155.233.160.1 to 155.233.161.254155.233.161.255510
210155.233.162.0/23155.233.162.1 to 155.233.163.254155.233.163.255510
211155.233.164.0/23155.233.164.1 to 155.233.165.254155.233.165.255510
212155.233.166.0/23155.233.166.1 to 155.233.167.254155.233.167.255510
213155.233.168.0/23155.233.168.1 to 155.233.169.254155.233.169.255510
214155.233.170.0/23155.233.170.1 to 155.233.171.254155.233.171.255510
215155.233.172.0/23155.233.172.1 to 155.233.173.254155.233.173.255510
216155.233.174.0/23155.233.174.1 to 155.233.175.254155.233.175.255510
217155.233.176.0/23155.233.176.1 to 155.233.177.254155.233.177.255510
218155.233.178.0/23155.233.178.1 to 155.233.179.254155.233.179.255510
219155.233.180.0/23155.233.180.1 to 155.233.181.254155.233.181.255510
220155.233.182.0/23155.233.182.1 to 155.233.183.254155.233.183.255510
221155.233.184.0/23155.233.184.1 to 155.233.185.254155.233.185.255510
222155.233.186.0/23155.233.186.1 to 155.233.187.254155.233.187.255510
223155.233.188.0/23155.233.188.1 to 155.233.189.254155.233.189.255510
224155.233.190.0/23155.233.190.1 to 155.233.191.254155.233.191.255510
225155.233.192.0/23155.233.192.1 to 155.233.193.254155.233.193.255510
226155.233.194.0/23155.233.194.1 to 155.233.195.254155.233.195.255510
227155.233.196.0/23155.233.196.1 to 155.233.197.254155.233.197.255510
228155.233.198.0/23155.233.198.1 to 155.233.199.254155.233.199.255510
229155.233.200.0/23155.233.200.1 to 155.233.201.254155.233.201.255510
230155.233.202.0/23155.233.202.1 to 155.233.203.254155.233.203.255510
231155.233.204.0/23155.233.204.1 to 155.233.205.254155.233.205.255510
232155.233.206.0/23155.233.206.1 to 155.233.207.254155.233.207.255510
233155.233.208.0/23155.233.208.1 to 155.233.209.254155.233.209.255510
234155.233.210.0/23155.233.210.1 to 155.233.211.254155.233.211.255510
235155.233.212.0/23155.233.212.1 to 155.233.213.254155.233.213.255510
236155.233.214.0/23155.233.214.1 to 155.233.215.254155.233.215.255510
237155.233.216.0/23155.233.216.1 to 155.233.217.254155.233.217.255510
238155.233.218.0/23155.233.218.1 to 155.233.219.254155.233.219.255510
239155.233.220.0/23155.233.220.1 to 155.233.221.254155.233.221.255510
240155.233.222.0/23155.233.222.1 to 155.233.223.254155.233.223.255510
241155.233.224.0/23155.233.224.1 to 155.233.225.254155.233.225.255510
242155.233.226.0/23155.233.226.1 to 155.233.227.254155.233.227.255510
243155.233.228.0/23155.233.228.1 to 155.233.229.254155.233.229.255510
244155.233.230.0/23155.233.230.1 to 155.233.231.254155.233.231.255510
245155.233.232.0/23155.233.232.1 to 155.233.233.254155.233.233.255510
246155.233.234.0/23155.233.234.1 to 155.233.235.254155.233.235.255510
247155.233.236.0/23155.233.236.1 to 155.233.237.254155.233.237.255510
248155.233.238.0/23155.233.238.1 to 155.233.239.254155.233.239.255510
249155.233.240.0/23155.233.240.1 to 155.233.241.254155.233.241.255510
250155.233.242.0/23155.233.242.1 to 155.233.243.254155.233.243.255510
251155.233.244.0/23155.233.244.1 to 155.233.245.254155.233.245.255510
252155.233.246.0/23155.233.246.1 to 155.233.247.254155.233.247.255510
253155.233.248.0/23155.233.248.1 to 155.233.249.254155.233.249.255510
254155.233.250.0/23155.233.250.1 to 155.233.251.254155.233.251.255510
255155.233.252.0/23155.233.252.1 to 155.233.253.254155.233.253.255510
256155.233.254.0/23155.233.254.1 to 155.233.255.254155.233.255.255510

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.