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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.

Network155.26.0.0/15
Usable hosts131,070
Subnet mask255.254.0.0
Addresses131,072
Network address
155.26.0.0
Broadcast address
155.27.255.255
First usable
155.26.0.1
Last usable
155.27.255.254
Usable hosts
131,070 (131,072 less the network and broadcast addresses)
Subnet mask
255.254.0.0
Wildcard mask
0.1.255.255 (Cisco ACLs, OSPF)
Prefix length
/15
Type
Public public
Old class
B (default /16)
As numbers
Hex 9B1A0000 · Integer 2602172416 to 2602303487
Reverse DNS zones
26.155.in-addr.arpa
27.155.in-addr.arpa
/15 is not on a 8-bit boundary, so it takes 2 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address10011011.00011010.00000000.00000000155.26.0.0
Subnet mask11111111.11111110.00000000.00000000255.254.0.0
Network10011011.00011010.00000000.00000000155.26.0.0
Broadcast10011011.00011011.11111111.11111111155.27.255.255
Split into smaller subnets/24
/16 (2)/17 (4)/18 (8)/19 (16)/20 (32)/21 (64)/22 (128)/23 (256)/24 (512)/25 (1,024)/26 (2,048)/27 (4,096)

155.26.0.0/15 makes 512 subnets of /24; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1155.26.0.0/24155.26.0.1 to 155.26.0.254155.26.0.255254
2155.26.1.0/24155.26.1.1 to 155.26.1.254155.26.1.255254
3155.26.2.0/24155.26.2.1 to 155.26.2.254155.26.2.255254
4155.26.3.0/24155.26.3.1 to 155.26.3.254155.26.3.255254
5155.26.4.0/24155.26.4.1 to 155.26.4.254155.26.4.255254
6155.26.5.0/24155.26.5.1 to 155.26.5.254155.26.5.255254
7155.26.6.0/24155.26.6.1 to 155.26.6.254155.26.6.255254
8155.26.7.0/24155.26.7.1 to 155.26.7.254155.26.7.255254
9155.26.8.0/24155.26.8.1 to 155.26.8.254155.26.8.255254
10155.26.9.0/24155.26.9.1 to 155.26.9.254155.26.9.255254
11155.26.10.0/24155.26.10.1 to 155.26.10.254155.26.10.255254
12155.26.11.0/24155.26.11.1 to 155.26.11.254155.26.11.255254
13155.26.12.0/24155.26.12.1 to 155.26.12.254155.26.12.255254
14155.26.13.0/24155.26.13.1 to 155.26.13.254155.26.13.255254
15155.26.14.0/24155.26.14.1 to 155.26.14.254155.26.14.255254
16155.26.15.0/24155.26.15.1 to 155.26.15.254155.26.15.255254
17155.26.16.0/24155.26.16.1 to 155.26.16.254155.26.16.255254
18155.26.17.0/24155.26.17.1 to 155.26.17.254155.26.17.255254
19155.26.18.0/24155.26.18.1 to 155.26.18.254155.26.18.255254
20155.26.19.0/24155.26.19.1 to 155.26.19.254155.26.19.255254
21155.26.20.0/24155.26.20.1 to 155.26.20.254155.26.20.255254
22155.26.21.0/24155.26.21.1 to 155.26.21.254155.26.21.255254
23155.26.22.0/24155.26.22.1 to 155.26.22.254155.26.22.255254
24155.26.23.0/24155.26.23.1 to 155.26.23.254155.26.23.255254
25155.26.24.0/24155.26.24.1 to 155.26.24.254155.26.24.255254
26155.26.25.0/24155.26.25.1 to 155.26.25.254155.26.25.255254
27155.26.26.0/24155.26.26.1 to 155.26.26.254155.26.26.255254
28155.26.27.0/24155.26.27.1 to 155.26.27.254155.26.27.255254
29155.26.28.0/24155.26.28.1 to 155.26.28.254155.26.28.255254
30155.26.29.0/24155.26.29.1 to 155.26.29.254155.26.29.255254
31155.26.30.0/24155.26.30.1 to 155.26.30.254155.26.30.255254
32155.26.31.0/24155.26.31.1 to 155.26.31.254155.26.31.255254
33155.26.32.0/24155.26.32.1 to 155.26.32.254155.26.32.255254
34155.26.33.0/24155.26.33.1 to 155.26.33.254155.26.33.255254
35155.26.34.0/24155.26.34.1 to 155.26.34.254155.26.34.255254
36155.26.35.0/24155.26.35.1 to 155.26.35.254155.26.35.255254
37155.26.36.0/24155.26.36.1 to 155.26.36.254155.26.36.255254
38155.26.37.0/24155.26.37.1 to 155.26.37.254155.26.37.255254
39155.26.38.0/24155.26.38.1 to 155.26.38.254155.26.38.255254
40155.26.39.0/24155.26.39.1 to 155.26.39.254155.26.39.255254
41155.26.40.0/24155.26.40.1 to 155.26.40.254155.26.40.255254
42155.26.41.0/24155.26.41.1 to 155.26.41.254155.26.41.255254
43155.26.42.0/24155.26.42.1 to 155.26.42.254155.26.42.255254
44155.26.43.0/24155.26.43.1 to 155.26.43.254155.26.43.255254
45155.26.44.0/24155.26.44.1 to 155.26.44.254155.26.44.255254
46155.26.45.0/24155.26.45.1 to 155.26.45.254155.26.45.255254
47155.26.46.0/24155.26.46.1 to 155.26.46.254155.26.46.255254
48155.26.47.0/24155.26.47.1 to 155.26.47.254155.26.47.255254
49155.26.48.0/24155.26.48.1 to 155.26.48.254155.26.48.255254
50155.26.49.0/24155.26.49.1 to 155.26.49.254155.26.49.255254
51155.26.50.0/24155.26.50.1 to 155.26.50.254155.26.50.255254
52155.26.51.0/24155.26.51.1 to 155.26.51.254155.26.51.255254
53155.26.52.0/24155.26.52.1 to 155.26.52.254155.26.52.255254
54155.26.53.0/24155.26.53.1 to 155.26.53.254155.26.53.255254
55155.26.54.0/24155.26.54.1 to 155.26.54.254155.26.54.255254
56155.26.55.0/24155.26.55.1 to 155.26.55.254155.26.55.255254
57155.26.56.0/24155.26.56.1 to 155.26.56.254155.26.56.255254
58155.26.57.0/24155.26.57.1 to 155.26.57.254155.26.57.255254
59155.26.58.0/24155.26.58.1 to 155.26.58.254155.26.58.255254
60155.26.59.0/24155.26.59.1 to 155.26.59.254155.26.59.255254
61155.26.60.0/24155.26.60.1 to 155.26.60.254155.26.60.255254
62155.26.61.0/24155.26.61.1 to 155.26.61.254155.26.61.255254
63155.26.62.0/24155.26.62.1 to 155.26.62.254155.26.62.255254
64155.26.63.0/24155.26.63.1 to 155.26.63.254155.26.63.255254
65155.26.64.0/24155.26.64.1 to 155.26.64.254155.26.64.255254
66155.26.65.0/24155.26.65.1 to 155.26.65.254155.26.65.255254
67155.26.66.0/24155.26.66.1 to 155.26.66.254155.26.66.255254
68155.26.67.0/24155.26.67.1 to 155.26.67.254155.26.67.255254
69155.26.68.0/24155.26.68.1 to 155.26.68.254155.26.68.255254
70155.26.69.0/24155.26.69.1 to 155.26.69.254155.26.69.255254
71155.26.70.0/24155.26.70.1 to 155.26.70.254155.26.70.255254
72155.26.71.0/24155.26.71.1 to 155.26.71.254155.26.71.255254
73155.26.72.0/24155.26.72.1 to 155.26.72.254155.26.72.255254
74155.26.73.0/24155.26.73.1 to 155.26.73.254155.26.73.255254
75155.26.74.0/24155.26.74.1 to 155.26.74.254155.26.74.255254
76155.26.75.0/24155.26.75.1 to 155.26.75.254155.26.75.255254
77155.26.76.0/24155.26.76.1 to 155.26.76.254155.26.76.255254
78155.26.77.0/24155.26.77.1 to 155.26.77.254155.26.77.255254
79155.26.78.0/24155.26.78.1 to 155.26.78.254155.26.78.255254
80155.26.79.0/24155.26.79.1 to 155.26.79.254155.26.79.255254
81155.26.80.0/24155.26.80.1 to 155.26.80.254155.26.80.255254
82155.26.81.0/24155.26.81.1 to 155.26.81.254155.26.81.255254
83155.26.82.0/24155.26.82.1 to 155.26.82.254155.26.82.255254
84155.26.83.0/24155.26.83.1 to 155.26.83.254155.26.83.255254
85155.26.84.0/24155.26.84.1 to 155.26.84.254155.26.84.255254
86155.26.85.0/24155.26.85.1 to 155.26.85.254155.26.85.255254
87155.26.86.0/24155.26.86.1 to 155.26.86.254155.26.86.255254
88155.26.87.0/24155.26.87.1 to 155.26.87.254155.26.87.255254
89155.26.88.0/24155.26.88.1 to 155.26.88.254155.26.88.255254
90155.26.89.0/24155.26.89.1 to 155.26.89.254155.26.89.255254
91155.26.90.0/24155.26.90.1 to 155.26.90.254155.26.90.255254
92155.26.91.0/24155.26.91.1 to 155.26.91.254155.26.91.255254
93155.26.92.0/24155.26.92.1 to 155.26.92.254155.26.92.255254
94155.26.93.0/24155.26.93.1 to 155.26.93.254155.26.93.255254
95155.26.94.0/24155.26.94.1 to 155.26.94.254155.26.94.255254
96155.26.95.0/24155.26.95.1 to 155.26.95.254155.26.95.255254
97155.26.96.0/24155.26.96.1 to 155.26.96.254155.26.96.255254
98155.26.97.0/24155.26.97.1 to 155.26.97.254155.26.97.255254
99155.26.98.0/24155.26.98.1 to 155.26.98.254155.26.98.255254
100155.26.99.0/24155.26.99.1 to 155.26.99.254155.26.99.255254
101155.26.100.0/24155.26.100.1 to 155.26.100.254155.26.100.255254
102155.26.101.0/24155.26.101.1 to 155.26.101.254155.26.101.255254
103155.26.102.0/24155.26.102.1 to 155.26.102.254155.26.102.255254
104155.26.103.0/24155.26.103.1 to 155.26.103.254155.26.103.255254
105155.26.104.0/24155.26.104.1 to 155.26.104.254155.26.104.255254
106155.26.105.0/24155.26.105.1 to 155.26.105.254155.26.105.255254
107155.26.106.0/24155.26.106.1 to 155.26.106.254155.26.106.255254
108155.26.107.0/24155.26.107.1 to 155.26.107.254155.26.107.255254
109155.26.108.0/24155.26.108.1 to 155.26.108.254155.26.108.255254
110155.26.109.0/24155.26.109.1 to 155.26.109.254155.26.109.255254
111155.26.110.0/24155.26.110.1 to 155.26.110.254155.26.110.255254
112155.26.111.0/24155.26.111.1 to 155.26.111.254155.26.111.255254
113155.26.112.0/24155.26.112.1 to 155.26.112.254155.26.112.255254
114155.26.113.0/24155.26.113.1 to 155.26.113.254155.26.113.255254
115155.26.114.0/24155.26.114.1 to 155.26.114.254155.26.114.255254
116155.26.115.0/24155.26.115.1 to 155.26.115.254155.26.115.255254
117155.26.116.0/24155.26.116.1 to 155.26.116.254155.26.116.255254
118155.26.117.0/24155.26.117.1 to 155.26.117.254155.26.117.255254
119155.26.118.0/24155.26.118.1 to 155.26.118.254155.26.118.255254
120155.26.119.0/24155.26.119.1 to 155.26.119.254155.26.119.255254
121155.26.120.0/24155.26.120.1 to 155.26.120.254155.26.120.255254
122155.26.121.0/24155.26.121.1 to 155.26.121.254155.26.121.255254
123155.26.122.0/24155.26.122.1 to 155.26.122.254155.26.122.255254
124155.26.123.0/24155.26.123.1 to 155.26.123.254155.26.123.255254
125155.26.124.0/24155.26.124.1 to 155.26.124.254155.26.124.255254
126155.26.125.0/24155.26.125.1 to 155.26.125.254155.26.125.255254
127155.26.126.0/24155.26.126.1 to 155.26.126.254155.26.126.255254
128155.26.127.0/24155.26.127.1 to 155.26.127.254155.26.127.255254
129155.26.128.0/24155.26.128.1 to 155.26.128.254155.26.128.255254
130155.26.129.0/24155.26.129.1 to 155.26.129.254155.26.129.255254
131155.26.130.0/24155.26.130.1 to 155.26.130.254155.26.130.255254
132155.26.131.0/24155.26.131.1 to 155.26.131.254155.26.131.255254
133155.26.132.0/24155.26.132.1 to 155.26.132.254155.26.132.255254
134155.26.133.0/24155.26.133.1 to 155.26.133.254155.26.133.255254
135155.26.134.0/24155.26.134.1 to 155.26.134.254155.26.134.255254
136155.26.135.0/24155.26.135.1 to 155.26.135.254155.26.135.255254
137155.26.136.0/24155.26.136.1 to 155.26.136.254155.26.136.255254
138155.26.137.0/24155.26.137.1 to 155.26.137.254155.26.137.255254
139155.26.138.0/24155.26.138.1 to 155.26.138.254155.26.138.255254
140155.26.139.0/24155.26.139.1 to 155.26.139.254155.26.139.255254
141155.26.140.0/24155.26.140.1 to 155.26.140.254155.26.140.255254
142155.26.141.0/24155.26.141.1 to 155.26.141.254155.26.141.255254
143155.26.142.0/24155.26.142.1 to 155.26.142.254155.26.142.255254
144155.26.143.0/24155.26.143.1 to 155.26.143.254155.26.143.255254
145155.26.144.0/24155.26.144.1 to 155.26.144.254155.26.144.255254
146155.26.145.0/24155.26.145.1 to 155.26.145.254155.26.145.255254
147155.26.146.0/24155.26.146.1 to 155.26.146.254155.26.146.255254
148155.26.147.0/24155.26.147.1 to 155.26.147.254155.26.147.255254
149155.26.148.0/24155.26.148.1 to 155.26.148.254155.26.148.255254
150155.26.149.0/24155.26.149.1 to 155.26.149.254155.26.149.255254
151155.26.150.0/24155.26.150.1 to 155.26.150.254155.26.150.255254
152155.26.151.0/24155.26.151.1 to 155.26.151.254155.26.151.255254
153155.26.152.0/24155.26.152.1 to 155.26.152.254155.26.152.255254
154155.26.153.0/24155.26.153.1 to 155.26.153.254155.26.153.255254
155155.26.154.0/24155.26.154.1 to 155.26.154.254155.26.154.255254
156155.26.155.0/24155.26.155.1 to 155.26.155.254155.26.155.255254
157155.26.156.0/24155.26.156.1 to 155.26.156.254155.26.156.255254
158155.26.157.0/24155.26.157.1 to 155.26.157.254155.26.157.255254
159155.26.158.0/24155.26.158.1 to 155.26.158.254155.26.158.255254
160155.26.159.0/24155.26.159.1 to 155.26.159.254155.26.159.255254
161155.26.160.0/24155.26.160.1 to 155.26.160.254155.26.160.255254
162155.26.161.0/24155.26.161.1 to 155.26.161.254155.26.161.255254
163155.26.162.0/24155.26.162.1 to 155.26.162.254155.26.162.255254
164155.26.163.0/24155.26.163.1 to 155.26.163.254155.26.163.255254
165155.26.164.0/24155.26.164.1 to 155.26.164.254155.26.164.255254
166155.26.165.0/24155.26.165.1 to 155.26.165.254155.26.165.255254
167155.26.166.0/24155.26.166.1 to 155.26.166.254155.26.166.255254
168155.26.167.0/24155.26.167.1 to 155.26.167.254155.26.167.255254
169155.26.168.0/24155.26.168.1 to 155.26.168.254155.26.168.255254
170155.26.169.0/24155.26.169.1 to 155.26.169.254155.26.169.255254
171155.26.170.0/24155.26.170.1 to 155.26.170.254155.26.170.255254
172155.26.171.0/24155.26.171.1 to 155.26.171.254155.26.171.255254
173155.26.172.0/24155.26.172.1 to 155.26.172.254155.26.172.255254
174155.26.173.0/24155.26.173.1 to 155.26.173.254155.26.173.255254
175155.26.174.0/24155.26.174.1 to 155.26.174.254155.26.174.255254
176155.26.175.0/24155.26.175.1 to 155.26.175.254155.26.175.255254
177155.26.176.0/24155.26.176.1 to 155.26.176.254155.26.176.255254
178155.26.177.0/24155.26.177.1 to 155.26.177.254155.26.177.255254
179155.26.178.0/24155.26.178.1 to 155.26.178.254155.26.178.255254
180155.26.179.0/24155.26.179.1 to 155.26.179.254155.26.179.255254
181155.26.180.0/24155.26.180.1 to 155.26.180.254155.26.180.255254
182155.26.181.0/24155.26.181.1 to 155.26.181.254155.26.181.255254
183155.26.182.0/24155.26.182.1 to 155.26.182.254155.26.182.255254
184155.26.183.0/24155.26.183.1 to 155.26.183.254155.26.183.255254
185155.26.184.0/24155.26.184.1 to 155.26.184.254155.26.184.255254
186155.26.185.0/24155.26.185.1 to 155.26.185.254155.26.185.255254
187155.26.186.0/24155.26.186.1 to 155.26.186.254155.26.186.255254
188155.26.187.0/24155.26.187.1 to 155.26.187.254155.26.187.255254
189155.26.188.0/24155.26.188.1 to 155.26.188.254155.26.188.255254
190155.26.189.0/24155.26.189.1 to 155.26.189.254155.26.189.255254
191155.26.190.0/24155.26.190.1 to 155.26.190.254155.26.190.255254
192155.26.191.0/24155.26.191.1 to 155.26.191.254155.26.191.255254
193155.26.192.0/24155.26.192.1 to 155.26.192.254155.26.192.255254
194155.26.193.0/24155.26.193.1 to 155.26.193.254155.26.193.255254
195155.26.194.0/24155.26.194.1 to 155.26.194.254155.26.194.255254
196155.26.195.0/24155.26.195.1 to 155.26.195.254155.26.195.255254
197155.26.196.0/24155.26.196.1 to 155.26.196.254155.26.196.255254
198155.26.197.0/24155.26.197.1 to 155.26.197.254155.26.197.255254
199155.26.198.0/24155.26.198.1 to 155.26.198.254155.26.198.255254
200155.26.199.0/24155.26.199.1 to 155.26.199.254155.26.199.255254
201155.26.200.0/24155.26.200.1 to 155.26.200.254155.26.200.255254
202155.26.201.0/24155.26.201.1 to 155.26.201.254155.26.201.255254
203155.26.202.0/24155.26.202.1 to 155.26.202.254155.26.202.255254
204155.26.203.0/24155.26.203.1 to 155.26.203.254155.26.203.255254
205155.26.204.0/24155.26.204.1 to 155.26.204.254155.26.204.255254
206155.26.205.0/24155.26.205.1 to 155.26.205.254155.26.205.255254
207155.26.206.0/24155.26.206.1 to 155.26.206.254155.26.206.255254
208155.26.207.0/24155.26.207.1 to 155.26.207.254155.26.207.255254
209155.26.208.0/24155.26.208.1 to 155.26.208.254155.26.208.255254
210155.26.209.0/24155.26.209.1 to 155.26.209.254155.26.209.255254
211155.26.210.0/24155.26.210.1 to 155.26.210.254155.26.210.255254
212155.26.211.0/24155.26.211.1 to 155.26.211.254155.26.211.255254
213155.26.212.0/24155.26.212.1 to 155.26.212.254155.26.212.255254
214155.26.213.0/24155.26.213.1 to 155.26.213.254155.26.213.255254
215155.26.214.0/24155.26.214.1 to 155.26.214.254155.26.214.255254
216155.26.215.0/24155.26.215.1 to 155.26.215.254155.26.215.255254
217155.26.216.0/24155.26.216.1 to 155.26.216.254155.26.216.255254
218155.26.217.0/24155.26.217.1 to 155.26.217.254155.26.217.255254
219155.26.218.0/24155.26.218.1 to 155.26.218.254155.26.218.255254
220155.26.219.0/24155.26.219.1 to 155.26.219.254155.26.219.255254
221155.26.220.0/24155.26.220.1 to 155.26.220.254155.26.220.255254
222155.26.221.0/24155.26.221.1 to 155.26.221.254155.26.221.255254
223155.26.222.0/24155.26.222.1 to 155.26.222.254155.26.222.255254
224155.26.223.0/24155.26.223.1 to 155.26.223.254155.26.223.255254
225155.26.224.0/24155.26.224.1 to 155.26.224.254155.26.224.255254
226155.26.225.0/24155.26.225.1 to 155.26.225.254155.26.225.255254
227155.26.226.0/24155.26.226.1 to 155.26.226.254155.26.226.255254
228155.26.227.0/24155.26.227.1 to 155.26.227.254155.26.227.255254
229155.26.228.0/24155.26.228.1 to 155.26.228.254155.26.228.255254
230155.26.229.0/24155.26.229.1 to 155.26.229.254155.26.229.255254
231155.26.230.0/24155.26.230.1 to 155.26.230.254155.26.230.255254
232155.26.231.0/24155.26.231.1 to 155.26.231.254155.26.231.255254
233155.26.232.0/24155.26.232.1 to 155.26.232.254155.26.232.255254
234155.26.233.0/24155.26.233.1 to 155.26.233.254155.26.233.255254
235155.26.234.0/24155.26.234.1 to 155.26.234.254155.26.234.255254
236155.26.235.0/24155.26.235.1 to 155.26.235.254155.26.235.255254
237155.26.236.0/24155.26.236.1 to 155.26.236.254155.26.236.255254
238155.26.237.0/24155.26.237.1 to 155.26.237.254155.26.237.255254
239155.26.238.0/24155.26.238.1 to 155.26.238.254155.26.238.255254
240155.26.239.0/24155.26.239.1 to 155.26.239.254155.26.239.255254
241155.26.240.0/24155.26.240.1 to 155.26.240.254155.26.240.255254
242155.26.241.0/24155.26.241.1 to 155.26.241.254155.26.241.255254
243155.26.242.0/24155.26.242.1 to 155.26.242.254155.26.242.255254
244155.26.243.0/24155.26.243.1 to 155.26.243.254155.26.243.255254
245155.26.244.0/24155.26.244.1 to 155.26.244.254155.26.244.255254
246155.26.245.0/24155.26.245.1 to 155.26.245.254155.26.245.255254
247155.26.246.0/24155.26.246.1 to 155.26.246.254155.26.246.255254
248155.26.247.0/24155.26.247.1 to 155.26.247.254155.26.247.255254
249155.26.248.0/24155.26.248.1 to 155.26.248.254155.26.248.255254
250155.26.249.0/24155.26.249.1 to 155.26.249.254155.26.249.255254
251155.26.250.0/24155.26.250.1 to 155.26.250.254155.26.250.255254
252155.26.251.0/24155.26.251.1 to 155.26.251.254155.26.251.255254
253155.26.252.0/24155.26.252.1 to 155.26.252.254155.26.252.255254
254155.26.253.0/24155.26.253.1 to 155.26.253.254155.26.253.255254
255155.26.254.0/24155.26.254.1 to 155.26.254.254155.26.254.255254
256155.26.255.0/24155.26.255.1 to 155.26.255.254155.26.255.255254

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.