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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.

Network233.48.0.0/12
Usable hosts1,048,574
Subnet mask255.240.0.0
Addresses1,048,576
Network address
233.48.0.0
Broadcast address
233.63.255.255
First usable
233.48.0.1
Last usable
233.63.255.254
Usable hosts
1,048,574 (1,048,576 less the network and broadcast addresses)
Subnet mask
255.240.0.0
Wildcard mask
0.15.255.255 (Cisco ACLs, OSPF)
Prefix length
/12
Type
Multicast 224.0.0.0/4
One-to-many traffic, such as IPTV and routing protocols
Old class
D (multicast)
As numbers
Hex E9300000 · Integer 3912237056 to 3913285631
Reverse DNS zones
48.233.in-addr.arpa
49.233.in-addr.arpa
50.233.in-addr.arpa
51.233.in-addr.arpa
52.233.in-addr.arpa
53.233.in-addr.arpa
54.233.in-addr.arpa
55.233.in-addr.arpa
56.233.in-addr.arpa
57.233.in-addr.arpa
58.233.in-addr.arpa
59.233.in-addr.arpa
60.233.in-addr.arpa
61.233.in-addr.arpa
62.233.in-addr.arpa
63.233.in-addr.arpa
/12 is not on a 8-bit boundary, so it takes 16 /16 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11101001.00110000.00000000.00000000233.48.0.0
Subnet mask11111111.11110000.00000000.00000000255.240.0.0
Network11101001.00110000.00000000.00000000233.48.0.0
Broadcast11101001.00111111.11111111.11111111233.63.255.255
Split into smaller subnets/23
/13 (2)/14 (4)/15 (8)/16 (16)/17 (32)/18 (64)/19 (128)/20 (256)/21 (512)/22 (1,024)/23 (2,048)/24 (4,096)

233.48.0.0/12 makes 2,048 subnets of /23; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1233.48.0.0/23233.48.0.1 to 233.48.1.254233.48.1.255510
2233.48.2.0/23233.48.2.1 to 233.48.3.254233.48.3.255510
3233.48.4.0/23233.48.4.1 to 233.48.5.254233.48.5.255510
4233.48.6.0/23233.48.6.1 to 233.48.7.254233.48.7.255510
5233.48.8.0/23233.48.8.1 to 233.48.9.254233.48.9.255510
6233.48.10.0/23233.48.10.1 to 233.48.11.254233.48.11.255510
7233.48.12.0/23233.48.12.1 to 233.48.13.254233.48.13.255510
8233.48.14.0/23233.48.14.1 to 233.48.15.254233.48.15.255510
9233.48.16.0/23233.48.16.1 to 233.48.17.254233.48.17.255510
10233.48.18.0/23233.48.18.1 to 233.48.19.254233.48.19.255510
11233.48.20.0/23233.48.20.1 to 233.48.21.254233.48.21.255510
12233.48.22.0/23233.48.22.1 to 233.48.23.254233.48.23.255510
13233.48.24.0/23233.48.24.1 to 233.48.25.254233.48.25.255510
14233.48.26.0/23233.48.26.1 to 233.48.27.254233.48.27.255510
15233.48.28.0/23233.48.28.1 to 233.48.29.254233.48.29.255510
16233.48.30.0/23233.48.30.1 to 233.48.31.254233.48.31.255510
17233.48.32.0/23233.48.32.1 to 233.48.33.254233.48.33.255510
18233.48.34.0/23233.48.34.1 to 233.48.35.254233.48.35.255510
19233.48.36.0/23233.48.36.1 to 233.48.37.254233.48.37.255510
20233.48.38.0/23233.48.38.1 to 233.48.39.254233.48.39.255510
21233.48.40.0/23233.48.40.1 to 233.48.41.254233.48.41.255510
22233.48.42.0/23233.48.42.1 to 233.48.43.254233.48.43.255510
23233.48.44.0/23233.48.44.1 to 233.48.45.254233.48.45.255510
24233.48.46.0/23233.48.46.1 to 233.48.47.254233.48.47.255510
25233.48.48.0/23233.48.48.1 to 233.48.49.254233.48.49.255510
26233.48.50.0/23233.48.50.1 to 233.48.51.254233.48.51.255510
27233.48.52.0/23233.48.52.1 to 233.48.53.254233.48.53.255510
28233.48.54.0/23233.48.54.1 to 233.48.55.254233.48.55.255510
29233.48.56.0/23233.48.56.1 to 233.48.57.254233.48.57.255510
30233.48.58.0/23233.48.58.1 to 233.48.59.254233.48.59.255510
31233.48.60.0/23233.48.60.1 to 233.48.61.254233.48.61.255510
32233.48.62.0/23233.48.62.1 to 233.48.63.254233.48.63.255510
33233.48.64.0/23233.48.64.1 to 233.48.65.254233.48.65.255510
34233.48.66.0/23233.48.66.1 to 233.48.67.254233.48.67.255510
35233.48.68.0/23233.48.68.1 to 233.48.69.254233.48.69.255510
36233.48.70.0/23233.48.70.1 to 233.48.71.254233.48.71.255510
37233.48.72.0/23233.48.72.1 to 233.48.73.254233.48.73.255510
38233.48.74.0/23233.48.74.1 to 233.48.75.254233.48.75.255510
39233.48.76.0/23233.48.76.1 to 233.48.77.254233.48.77.255510
40233.48.78.0/23233.48.78.1 to 233.48.79.254233.48.79.255510
41233.48.80.0/23233.48.80.1 to 233.48.81.254233.48.81.255510
42233.48.82.0/23233.48.82.1 to 233.48.83.254233.48.83.255510
43233.48.84.0/23233.48.84.1 to 233.48.85.254233.48.85.255510
44233.48.86.0/23233.48.86.1 to 233.48.87.254233.48.87.255510
45233.48.88.0/23233.48.88.1 to 233.48.89.254233.48.89.255510
46233.48.90.0/23233.48.90.1 to 233.48.91.254233.48.91.255510
47233.48.92.0/23233.48.92.1 to 233.48.93.254233.48.93.255510
48233.48.94.0/23233.48.94.1 to 233.48.95.254233.48.95.255510
49233.48.96.0/23233.48.96.1 to 233.48.97.254233.48.97.255510
50233.48.98.0/23233.48.98.1 to 233.48.99.254233.48.99.255510
51233.48.100.0/23233.48.100.1 to 233.48.101.254233.48.101.255510
52233.48.102.0/23233.48.102.1 to 233.48.103.254233.48.103.255510
53233.48.104.0/23233.48.104.1 to 233.48.105.254233.48.105.255510
54233.48.106.0/23233.48.106.1 to 233.48.107.254233.48.107.255510
55233.48.108.0/23233.48.108.1 to 233.48.109.254233.48.109.255510
56233.48.110.0/23233.48.110.1 to 233.48.111.254233.48.111.255510
57233.48.112.0/23233.48.112.1 to 233.48.113.254233.48.113.255510
58233.48.114.0/23233.48.114.1 to 233.48.115.254233.48.115.255510
59233.48.116.0/23233.48.116.1 to 233.48.117.254233.48.117.255510
60233.48.118.0/23233.48.118.1 to 233.48.119.254233.48.119.255510
61233.48.120.0/23233.48.120.1 to 233.48.121.254233.48.121.255510
62233.48.122.0/23233.48.122.1 to 233.48.123.254233.48.123.255510
63233.48.124.0/23233.48.124.1 to 233.48.125.254233.48.125.255510
64233.48.126.0/23233.48.126.1 to 233.48.127.254233.48.127.255510
65233.48.128.0/23233.48.128.1 to 233.48.129.254233.48.129.255510
66233.48.130.0/23233.48.130.1 to 233.48.131.254233.48.131.255510
67233.48.132.0/23233.48.132.1 to 233.48.133.254233.48.133.255510
68233.48.134.0/23233.48.134.1 to 233.48.135.254233.48.135.255510
69233.48.136.0/23233.48.136.1 to 233.48.137.254233.48.137.255510
70233.48.138.0/23233.48.138.1 to 233.48.139.254233.48.139.255510
71233.48.140.0/23233.48.140.1 to 233.48.141.254233.48.141.255510
72233.48.142.0/23233.48.142.1 to 233.48.143.254233.48.143.255510
73233.48.144.0/23233.48.144.1 to 233.48.145.254233.48.145.255510
74233.48.146.0/23233.48.146.1 to 233.48.147.254233.48.147.255510
75233.48.148.0/23233.48.148.1 to 233.48.149.254233.48.149.255510
76233.48.150.0/23233.48.150.1 to 233.48.151.254233.48.151.255510
77233.48.152.0/23233.48.152.1 to 233.48.153.254233.48.153.255510
78233.48.154.0/23233.48.154.1 to 233.48.155.254233.48.155.255510
79233.48.156.0/23233.48.156.1 to 233.48.157.254233.48.157.255510
80233.48.158.0/23233.48.158.1 to 233.48.159.254233.48.159.255510
81233.48.160.0/23233.48.160.1 to 233.48.161.254233.48.161.255510
82233.48.162.0/23233.48.162.1 to 233.48.163.254233.48.163.255510
83233.48.164.0/23233.48.164.1 to 233.48.165.254233.48.165.255510
84233.48.166.0/23233.48.166.1 to 233.48.167.254233.48.167.255510
85233.48.168.0/23233.48.168.1 to 233.48.169.254233.48.169.255510
86233.48.170.0/23233.48.170.1 to 233.48.171.254233.48.171.255510
87233.48.172.0/23233.48.172.1 to 233.48.173.254233.48.173.255510
88233.48.174.0/23233.48.174.1 to 233.48.175.254233.48.175.255510
89233.48.176.0/23233.48.176.1 to 233.48.177.254233.48.177.255510
90233.48.178.0/23233.48.178.1 to 233.48.179.254233.48.179.255510
91233.48.180.0/23233.48.180.1 to 233.48.181.254233.48.181.255510
92233.48.182.0/23233.48.182.1 to 233.48.183.254233.48.183.255510
93233.48.184.0/23233.48.184.1 to 233.48.185.254233.48.185.255510
94233.48.186.0/23233.48.186.1 to 233.48.187.254233.48.187.255510
95233.48.188.0/23233.48.188.1 to 233.48.189.254233.48.189.255510
96233.48.190.0/23233.48.190.1 to 233.48.191.254233.48.191.255510
97233.48.192.0/23233.48.192.1 to 233.48.193.254233.48.193.255510
98233.48.194.0/23233.48.194.1 to 233.48.195.254233.48.195.255510
99233.48.196.0/23233.48.196.1 to 233.48.197.254233.48.197.255510
100233.48.198.0/23233.48.198.1 to 233.48.199.254233.48.199.255510
101233.48.200.0/23233.48.200.1 to 233.48.201.254233.48.201.255510
102233.48.202.0/23233.48.202.1 to 233.48.203.254233.48.203.255510
103233.48.204.0/23233.48.204.1 to 233.48.205.254233.48.205.255510
104233.48.206.0/23233.48.206.1 to 233.48.207.254233.48.207.255510
105233.48.208.0/23233.48.208.1 to 233.48.209.254233.48.209.255510
106233.48.210.0/23233.48.210.1 to 233.48.211.254233.48.211.255510
107233.48.212.0/23233.48.212.1 to 233.48.213.254233.48.213.255510
108233.48.214.0/23233.48.214.1 to 233.48.215.254233.48.215.255510
109233.48.216.0/23233.48.216.1 to 233.48.217.254233.48.217.255510
110233.48.218.0/23233.48.218.1 to 233.48.219.254233.48.219.255510
111233.48.220.0/23233.48.220.1 to 233.48.221.254233.48.221.255510
112233.48.222.0/23233.48.222.1 to 233.48.223.254233.48.223.255510
113233.48.224.0/23233.48.224.1 to 233.48.225.254233.48.225.255510
114233.48.226.0/23233.48.226.1 to 233.48.227.254233.48.227.255510
115233.48.228.0/23233.48.228.1 to 233.48.229.254233.48.229.255510
116233.48.230.0/23233.48.230.1 to 233.48.231.254233.48.231.255510
117233.48.232.0/23233.48.232.1 to 233.48.233.254233.48.233.255510
118233.48.234.0/23233.48.234.1 to 233.48.235.254233.48.235.255510
119233.48.236.0/23233.48.236.1 to 233.48.237.254233.48.237.255510
120233.48.238.0/23233.48.238.1 to 233.48.239.254233.48.239.255510
121233.48.240.0/23233.48.240.1 to 233.48.241.254233.48.241.255510
122233.48.242.0/23233.48.242.1 to 233.48.243.254233.48.243.255510
123233.48.244.0/23233.48.244.1 to 233.48.245.254233.48.245.255510
124233.48.246.0/23233.48.246.1 to 233.48.247.254233.48.247.255510
125233.48.248.0/23233.48.248.1 to 233.48.249.254233.48.249.255510
126233.48.250.0/23233.48.250.1 to 233.48.251.254233.48.251.255510
127233.48.252.0/23233.48.252.1 to 233.48.253.254233.48.253.255510
128233.48.254.0/23233.48.254.1 to 233.48.255.254233.48.255.255510
129233.49.0.0/23233.49.0.1 to 233.49.1.254233.49.1.255510
130233.49.2.0/23233.49.2.1 to 233.49.3.254233.49.3.255510
131233.49.4.0/23233.49.4.1 to 233.49.5.254233.49.5.255510
132233.49.6.0/23233.49.6.1 to 233.49.7.254233.49.7.255510
133233.49.8.0/23233.49.8.1 to 233.49.9.254233.49.9.255510
134233.49.10.0/23233.49.10.1 to 233.49.11.254233.49.11.255510
135233.49.12.0/23233.49.12.1 to 233.49.13.254233.49.13.255510
136233.49.14.0/23233.49.14.1 to 233.49.15.254233.49.15.255510
137233.49.16.0/23233.49.16.1 to 233.49.17.254233.49.17.255510
138233.49.18.0/23233.49.18.1 to 233.49.19.254233.49.19.255510
139233.49.20.0/23233.49.20.1 to 233.49.21.254233.49.21.255510
140233.49.22.0/23233.49.22.1 to 233.49.23.254233.49.23.255510
141233.49.24.0/23233.49.24.1 to 233.49.25.254233.49.25.255510
142233.49.26.0/23233.49.26.1 to 233.49.27.254233.49.27.255510
143233.49.28.0/23233.49.28.1 to 233.49.29.254233.49.29.255510
144233.49.30.0/23233.49.30.1 to 233.49.31.254233.49.31.255510
145233.49.32.0/23233.49.32.1 to 233.49.33.254233.49.33.255510
146233.49.34.0/23233.49.34.1 to 233.49.35.254233.49.35.255510
147233.49.36.0/23233.49.36.1 to 233.49.37.254233.49.37.255510
148233.49.38.0/23233.49.38.1 to 233.49.39.254233.49.39.255510
149233.49.40.0/23233.49.40.1 to 233.49.41.254233.49.41.255510
150233.49.42.0/23233.49.42.1 to 233.49.43.254233.49.43.255510
151233.49.44.0/23233.49.44.1 to 233.49.45.254233.49.45.255510
152233.49.46.0/23233.49.46.1 to 233.49.47.254233.49.47.255510
153233.49.48.0/23233.49.48.1 to 233.49.49.254233.49.49.255510
154233.49.50.0/23233.49.50.1 to 233.49.51.254233.49.51.255510
155233.49.52.0/23233.49.52.1 to 233.49.53.254233.49.53.255510
156233.49.54.0/23233.49.54.1 to 233.49.55.254233.49.55.255510
157233.49.56.0/23233.49.56.1 to 233.49.57.254233.49.57.255510
158233.49.58.0/23233.49.58.1 to 233.49.59.254233.49.59.255510
159233.49.60.0/23233.49.60.1 to 233.49.61.254233.49.61.255510
160233.49.62.0/23233.49.62.1 to 233.49.63.254233.49.63.255510
161233.49.64.0/23233.49.64.1 to 233.49.65.254233.49.65.255510
162233.49.66.0/23233.49.66.1 to 233.49.67.254233.49.67.255510
163233.49.68.0/23233.49.68.1 to 233.49.69.254233.49.69.255510
164233.49.70.0/23233.49.70.1 to 233.49.71.254233.49.71.255510
165233.49.72.0/23233.49.72.1 to 233.49.73.254233.49.73.255510
166233.49.74.0/23233.49.74.1 to 233.49.75.254233.49.75.255510
167233.49.76.0/23233.49.76.1 to 233.49.77.254233.49.77.255510
168233.49.78.0/23233.49.78.1 to 233.49.79.254233.49.79.255510
169233.49.80.0/23233.49.80.1 to 233.49.81.254233.49.81.255510
170233.49.82.0/23233.49.82.1 to 233.49.83.254233.49.83.255510
171233.49.84.0/23233.49.84.1 to 233.49.85.254233.49.85.255510
172233.49.86.0/23233.49.86.1 to 233.49.87.254233.49.87.255510
173233.49.88.0/23233.49.88.1 to 233.49.89.254233.49.89.255510
174233.49.90.0/23233.49.90.1 to 233.49.91.254233.49.91.255510
175233.49.92.0/23233.49.92.1 to 233.49.93.254233.49.93.255510
176233.49.94.0/23233.49.94.1 to 233.49.95.254233.49.95.255510
177233.49.96.0/23233.49.96.1 to 233.49.97.254233.49.97.255510
178233.49.98.0/23233.49.98.1 to 233.49.99.254233.49.99.255510
179233.49.100.0/23233.49.100.1 to 233.49.101.254233.49.101.255510
180233.49.102.0/23233.49.102.1 to 233.49.103.254233.49.103.255510
181233.49.104.0/23233.49.104.1 to 233.49.105.254233.49.105.255510
182233.49.106.0/23233.49.106.1 to 233.49.107.254233.49.107.255510
183233.49.108.0/23233.49.108.1 to 233.49.109.254233.49.109.255510
184233.49.110.0/23233.49.110.1 to 233.49.111.254233.49.111.255510
185233.49.112.0/23233.49.112.1 to 233.49.113.254233.49.113.255510
186233.49.114.0/23233.49.114.1 to 233.49.115.254233.49.115.255510
187233.49.116.0/23233.49.116.1 to 233.49.117.254233.49.117.255510
188233.49.118.0/23233.49.118.1 to 233.49.119.254233.49.119.255510
189233.49.120.0/23233.49.120.1 to 233.49.121.254233.49.121.255510
190233.49.122.0/23233.49.122.1 to 233.49.123.254233.49.123.255510
191233.49.124.0/23233.49.124.1 to 233.49.125.254233.49.125.255510
192233.49.126.0/23233.49.126.1 to 233.49.127.254233.49.127.255510
193233.49.128.0/23233.49.128.1 to 233.49.129.254233.49.129.255510
194233.49.130.0/23233.49.130.1 to 233.49.131.254233.49.131.255510
195233.49.132.0/23233.49.132.1 to 233.49.133.254233.49.133.255510
196233.49.134.0/23233.49.134.1 to 233.49.135.254233.49.135.255510
197233.49.136.0/23233.49.136.1 to 233.49.137.254233.49.137.255510
198233.49.138.0/23233.49.138.1 to 233.49.139.254233.49.139.255510
199233.49.140.0/23233.49.140.1 to 233.49.141.254233.49.141.255510
200233.49.142.0/23233.49.142.1 to 233.49.143.254233.49.143.255510
201233.49.144.0/23233.49.144.1 to 233.49.145.254233.49.145.255510
202233.49.146.0/23233.49.146.1 to 233.49.147.254233.49.147.255510
203233.49.148.0/23233.49.148.1 to 233.49.149.254233.49.149.255510
204233.49.150.0/23233.49.150.1 to 233.49.151.254233.49.151.255510
205233.49.152.0/23233.49.152.1 to 233.49.153.254233.49.153.255510
206233.49.154.0/23233.49.154.1 to 233.49.155.254233.49.155.255510
207233.49.156.0/23233.49.156.1 to 233.49.157.254233.49.157.255510
208233.49.158.0/23233.49.158.1 to 233.49.159.254233.49.159.255510
209233.49.160.0/23233.49.160.1 to 233.49.161.254233.49.161.255510
210233.49.162.0/23233.49.162.1 to 233.49.163.254233.49.163.255510
211233.49.164.0/23233.49.164.1 to 233.49.165.254233.49.165.255510
212233.49.166.0/23233.49.166.1 to 233.49.167.254233.49.167.255510
213233.49.168.0/23233.49.168.1 to 233.49.169.254233.49.169.255510
214233.49.170.0/23233.49.170.1 to 233.49.171.254233.49.171.255510
215233.49.172.0/23233.49.172.1 to 233.49.173.254233.49.173.255510
216233.49.174.0/23233.49.174.1 to 233.49.175.254233.49.175.255510
217233.49.176.0/23233.49.176.1 to 233.49.177.254233.49.177.255510
218233.49.178.0/23233.49.178.1 to 233.49.179.254233.49.179.255510
219233.49.180.0/23233.49.180.1 to 233.49.181.254233.49.181.255510
220233.49.182.0/23233.49.182.1 to 233.49.183.254233.49.183.255510
221233.49.184.0/23233.49.184.1 to 233.49.185.254233.49.185.255510
222233.49.186.0/23233.49.186.1 to 233.49.187.254233.49.187.255510
223233.49.188.0/23233.49.188.1 to 233.49.189.254233.49.189.255510
224233.49.190.0/23233.49.190.1 to 233.49.191.254233.49.191.255510
225233.49.192.0/23233.49.192.1 to 233.49.193.254233.49.193.255510
226233.49.194.0/23233.49.194.1 to 233.49.195.254233.49.195.255510
227233.49.196.0/23233.49.196.1 to 233.49.197.254233.49.197.255510
228233.49.198.0/23233.49.198.1 to 233.49.199.254233.49.199.255510
229233.49.200.0/23233.49.200.1 to 233.49.201.254233.49.201.255510
230233.49.202.0/23233.49.202.1 to 233.49.203.254233.49.203.255510
231233.49.204.0/23233.49.204.1 to 233.49.205.254233.49.205.255510
232233.49.206.0/23233.49.206.1 to 233.49.207.254233.49.207.255510
233233.49.208.0/23233.49.208.1 to 233.49.209.254233.49.209.255510
234233.49.210.0/23233.49.210.1 to 233.49.211.254233.49.211.255510
235233.49.212.0/23233.49.212.1 to 233.49.213.254233.49.213.255510
236233.49.214.0/23233.49.214.1 to 233.49.215.254233.49.215.255510
237233.49.216.0/23233.49.216.1 to 233.49.217.254233.49.217.255510
238233.49.218.0/23233.49.218.1 to 233.49.219.254233.49.219.255510
239233.49.220.0/23233.49.220.1 to 233.49.221.254233.49.221.255510
240233.49.222.0/23233.49.222.1 to 233.49.223.254233.49.223.255510
241233.49.224.0/23233.49.224.1 to 233.49.225.254233.49.225.255510
242233.49.226.0/23233.49.226.1 to 233.49.227.254233.49.227.255510
243233.49.228.0/23233.49.228.1 to 233.49.229.254233.49.229.255510
244233.49.230.0/23233.49.230.1 to 233.49.231.254233.49.231.255510
245233.49.232.0/23233.49.232.1 to 233.49.233.254233.49.233.255510
246233.49.234.0/23233.49.234.1 to 233.49.235.254233.49.235.255510
247233.49.236.0/23233.49.236.1 to 233.49.237.254233.49.237.255510
248233.49.238.0/23233.49.238.1 to 233.49.239.254233.49.239.255510
249233.49.240.0/23233.49.240.1 to 233.49.241.254233.49.241.255510
250233.49.242.0/23233.49.242.1 to 233.49.243.254233.49.243.255510
251233.49.244.0/23233.49.244.1 to 233.49.245.254233.49.245.255510
252233.49.246.0/23233.49.246.1 to 233.49.247.254233.49.247.255510
253233.49.248.0/23233.49.248.1 to 233.49.249.254233.49.249.255510
254233.49.250.0/23233.49.250.1 to 233.49.251.254233.49.251.255510
255233.49.252.0/23233.49.252.1 to 233.49.253.254233.49.253.255510
256233.49.254.0/23233.49.254.1 to 233.49.255.254233.49.255.255510

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.