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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.

Network252.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
252.0.0.0
Broadcast address
253.255.255.255
First usable
252.0.0.1
Last usable
253.255.255.254
Usable hosts
33,554,430 (33,554,432 less the network and broadcast addresses)
Subnet mask
254.0.0.0
Wildcard mask
1.255.255.255 (Cisco ACLs, OSPF)
Prefix length
/7
Type
Reserved 240.0.0.0/4
Future use; not usable on most systems
Old class
E (reserved)
As numbers
Hex FC000000 · Integer 4227858432 to 4261412863
Reverse DNS zones
252.in-addr.arpa
253.in-addr.arpa
/7 is not on a 8-bit boundary, so it takes 2 /8 zones.
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address11111100.00000000.00000000.00000000252.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network11111100.00000000.00000000.00000000252.0.0.0
Broadcast11111101.11111111.11111111.11111111253.255.255.255
Split into smaller subnets/15
/8 (2)/9 (4)/10 (8)/11 (16)/12 (32)/13 (64)/14 (128)/15 (256)/16 (512)/17 (1,024)/18 (2,048)/19 (4,096)

252.0.0.0/7 makes 256 subnets of /15.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1252.0.0.0/15252.0.0.1 to 252.1.255.254252.1.255.255131,070
2252.2.0.0/15252.2.0.1 to 252.3.255.254252.3.255.255131,070
3252.4.0.0/15252.4.0.1 to 252.5.255.254252.5.255.255131,070
4252.6.0.0/15252.6.0.1 to 252.7.255.254252.7.255.255131,070
5252.8.0.0/15252.8.0.1 to 252.9.255.254252.9.255.255131,070
6252.10.0.0/15252.10.0.1 to 252.11.255.254252.11.255.255131,070
7252.12.0.0/15252.12.0.1 to 252.13.255.254252.13.255.255131,070
8252.14.0.0/15252.14.0.1 to 252.15.255.254252.15.255.255131,070
9252.16.0.0/15252.16.0.1 to 252.17.255.254252.17.255.255131,070
10252.18.0.0/15252.18.0.1 to 252.19.255.254252.19.255.255131,070
11252.20.0.0/15252.20.0.1 to 252.21.255.254252.21.255.255131,070
12252.22.0.0/15252.22.0.1 to 252.23.255.254252.23.255.255131,070
13252.24.0.0/15252.24.0.1 to 252.25.255.254252.25.255.255131,070
14252.26.0.0/15252.26.0.1 to 252.27.255.254252.27.255.255131,070
15252.28.0.0/15252.28.0.1 to 252.29.255.254252.29.255.255131,070
16252.30.0.0/15252.30.0.1 to 252.31.255.254252.31.255.255131,070
17252.32.0.0/15252.32.0.1 to 252.33.255.254252.33.255.255131,070
18252.34.0.0/15252.34.0.1 to 252.35.255.254252.35.255.255131,070
19252.36.0.0/15252.36.0.1 to 252.37.255.254252.37.255.255131,070
20252.38.0.0/15252.38.0.1 to 252.39.255.254252.39.255.255131,070
21252.40.0.0/15252.40.0.1 to 252.41.255.254252.41.255.255131,070
22252.42.0.0/15252.42.0.1 to 252.43.255.254252.43.255.255131,070
23252.44.0.0/15252.44.0.1 to 252.45.255.254252.45.255.255131,070
24252.46.0.0/15252.46.0.1 to 252.47.255.254252.47.255.255131,070
25252.48.0.0/15252.48.0.1 to 252.49.255.254252.49.255.255131,070
26252.50.0.0/15252.50.0.1 to 252.51.255.254252.51.255.255131,070
27252.52.0.0/15252.52.0.1 to 252.53.255.254252.53.255.255131,070
28252.54.0.0/15252.54.0.1 to 252.55.255.254252.55.255.255131,070
29252.56.0.0/15252.56.0.1 to 252.57.255.254252.57.255.255131,070
30252.58.0.0/15252.58.0.1 to 252.59.255.254252.59.255.255131,070
31252.60.0.0/15252.60.0.1 to 252.61.255.254252.61.255.255131,070
32252.62.0.0/15252.62.0.1 to 252.63.255.254252.63.255.255131,070
33252.64.0.0/15252.64.0.1 to 252.65.255.254252.65.255.255131,070
34252.66.0.0/15252.66.0.1 to 252.67.255.254252.67.255.255131,070
35252.68.0.0/15252.68.0.1 to 252.69.255.254252.69.255.255131,070
36252.70.0.0/15252.70.0.1 to 252.71.255.254252.71.255.255131,070
37252.72.0.0/15252.72.0.1 to 252.73.255.254252.73.255.255131,070
38252.74.0.0/15252.74.0.1 to 252.75.255.254252.75.255.255131,070
39252.76.0.0/15252.76.0.1 to 252.77.255.254252.77.255.255131,070
40252.78.0.0/15252.78.0.1 to 252.79.255.254252.79.255.255131,070
41252.80.0.0/15252.80.0.1 to 252.81.255.254252.81.255.255131,070
42252.82.0.0/15252.82.0.1 to 252.83.255.254252.83.255.255131,070
43252.84.0.0/15252.84.0.1 to 252.85.255.254252.85.255.255131,070
44252.86.0.0/15252.86.0.1 to 252.87.255.254252.87.255.255131,070
45252.88.0.0/15252.88.0.1 to 252.89.255.254252.89.255.255131,070
46252.90.0.0/15252.90.0.1 to 252.91.255.254252.91.255.255131,070
47252.92.0.0/15252.92.0.1 to 252.93.255.254252.93.255.255131,070
48252.94.0.0/15252.94.0.1 to 252.95.255.254252.95.255.255131,070
49252.96.0.0/15252.96.0.1 to 252.97.255.254252.97.255.255131,070
50252.98.0.0/15252.98.0.1 to 252.99.255.254252.99.255.255131,070
51252.100.0.0/15252.100.0.1 to 252.101.255.254252.101.255.255131,070
52252.102.0.0/15252.102.0.1 to 252.103.255.254252.103.255.255131,070
53252.104.0.0/15252.104.0.1 to 252.105.255.254252.105.255.255131,070
54252.106.0.0/15252.106.0.1 to 252.107.255.254252.107.255.255131,070
55252.108.0.0/15252.108.0.1 to 252.109.255.254252.109.255.255131,070
56252.110.0.0/15252.110.0.1 to 252.111.255.254252.111.255.255131,070
57252.112.0.0/15252.112.0.1 to 252.113.255.254252.113.255.255131,070
58252.114.0.0/15252.114.0.1 to 252.115.255.254252.115.255.255131,070
59252.116.0.0/15252.116.0.1 to 252.117.255.254252.117.255.255131,070
60252.118.0.0/15252.118.0.1 to 252.119.255.254252.119.255.255131,070
61252.120.0.0/15252.120.0.1 to 252.121.255.254252.121.255.255131,070
62252.122.0.0/15252.122.0.1 to 252.123.255.254252.123.255.255131,070
63252.124.0.0/15252.124.0.1 to 252.125.255.254252.125.255.255131,070
64252.126.0.0/15252.126.0.1 to 252.127.255.254252.127.255.255131,070
65252.128.0.0/15252.128.0.1 to 252.129.255.254252.129.255.255131,070
66252.130.0.0/15252.130.0.1 to 252.131.255.254252.131.255.255131,070
67252.132.0.0/15252.132.0.1 to 252.133.255.254252.133.255.255131,070
68252.134.0.0/15252.134.0.1 to 252.135.255.254252.135.255.255131,070
69252.136.0.0/15252.136.0.1 to 252.137.255.254252.137.255.255131,070
70252.138.0.0/15252.138.0.1 to 252.139.255.254252.139.255.255131,070
71252.140.0.0/15252.140.0.1 to 252.141.255.254252.141.255.255131,070
72252.142.0.0/15252.142.0.1 to 252.143.255.254252.143.255.255131,070
73252.144.0.0/15252.144.0.1 to 252.145.255.254252.145.255.255131,070
74252.146.0.0/15252.146.0.1 to 252.147.255.254252.147.255.255131,070
75252.148.0.0/15252.148.0.1 to 252.149.255.254252.149.255.255131,070
76252.150.0.0/15252.150.0.1 to 252.151.255.254252.151.255.255131,070
77252.152.0.0/15252.152.0.1 to 252.153.255.254252.153.255.255131,070
78252.154.0.0/15252.154.0.1 to 252.155.255.254252.155.255.255131,070
79252.156.0.0/15252.156.0.1 to 252.157.255.254252.157.255.255131,070
80252.158.0.0/15252.158.0.1 to 252.159.255.254252.159.255.255131,070
81252.160.0.0/15252.160.0.1 to 252.161.255.254252.161.255.255131,070
82252.162.0.0/15252.162.0.1 to 252.163.255.254252.163.255.255131,070
83252.164.0.0/15252.164.0.1 to 252.165.255.254252.165.255.255131,070
84252.166.0.0/15252.166.0.1 to 252.167.255.254252.167.255.255131,070
85252.168.0.0/15252.168.0.1 to 252.169.255.254252.169.255.255131,070
86252.170.0.0/15252.170.0.1 to 252.171.255.254252.171.255.255131,070
87252.172.0.0/15252.172.0.1 to 252.173.255.254252.173.255.255131,070
88252.174.0.0/15252.174.0.1 to 252.175.255.254252.175.255.255131,070
89252.176.0.0/15252.176.0.1 to 252.177.255.254252.177.255.255131,070
90252.178.0.0/15252.178.0.1 to 252.179.255.254252.179.255.255131,070
91252.180.0.0/15252.180.0.1 to 252.181.255.254252.181.255.255131,070
92252.182.0.0/15252.182.0.1 to 252.183.255.254252.183.255.255131,070
93252.184.0.0/15252.184.0.1 to 252.185.255.254252.185.255.255131,070
94252.186.0.0/15252.186.0.1 to 252.187.255.254252.187.255.255131,070
95252.188.0.0/15252.188.0.1 to 252.189.255.254252.189.255.255131,070
96252.190.0.0/15252.190.0.1 to 252.191.255.254252.191.255.255131,070
97252.192.0.0/15252.192.0.1 to 252.193.255.254252.193.255.255131,070
98252.194.0.0/15252.194.0.1 to 252.195.255.254252.195.255.255131,070
99252.196.0.0/15252.196.0.1 to 252.197.255.254252.197.255.255131,070
100252.198.0.0/15252.198.0.1 to 252.199.255.254252.199.255.255131,070
101252.200.0.0/15252.200.0.1 to 252.201.255.254252.201.255.255131,070
102252.202.0.0/15252.202.0.1 to 252.203.255.254252.203.255.255131,070
103252.204.0.0/15252.204.0.1 to 252.205.255.254252.205.255.255131,070
104252.206.0.0/15252.206.0.1 to 252.207.255.254252.207.255.255131,070
105252.208.0.0/15252.208.0.1 to 252.209.255.254252.209.255.255131,070
106252.210.0.0/15252.210.0.1 to 252.211.255.254252.211.255.255131,070
107252.212.0.0/15252.212.0.1 to 252.213.255.254252.213.255.255131,070
108252.214.0.0/15252.214.0.1 to 252.215.255.254252.215.255.255131,070
109252.216.0.0/15252.216.0.1 to 252.217.255.254252.217.255.255131,070
110252.218.0.0/15252.218.0.1 to 252.219.255.254252.219.255.255131,070
111252.220.0.0/15252.220.0.1 to 252.221.255.254252.221.255.255131,070
112252.222.0.0/15252.222.0.1 to 252.223.255.254252.223.255.255131,070
113252.224.0.0/15252.224.0.1 to 252.225.255.254252.225.255.255131,070
114252.226.0.0/15252.226.0.1 to 252.227.255.254252.227.255.255131,070
115252.228.0.0/15252.228.0.1 to 252.229.255.254252.229.255.255131,070
116252.230.0.0/15252.230.0.1 to 252.231.255.254252.231.255.255131,070
117252.232.0.0/15252.232.0.1 to 252.233.255.254252.233.255.255131,070
118252.234.0.0/15252.234.0.1 to 252.235.255.254252.235.255.255131,070
119252.236.0.0/15252.236.0.1 to 252.237.255.254252.237.255.255131,070
120252.238.0.0/15252.238.0.1 to 252.239.255.254252.239.255.255131,070
121252.240.0.0/15252.240.0.1 to 252.241.255.254252.241.255.255131,070
122252.242.0.0/15252.242.0.1 to 252.243.255.254252.243.255.255131,070
123252.244.0.0/15252.244.0.1 to 252.245.255.254252.245.255.255131,070
124252.246.0.0/15252.246.0.1 to 252.247.255.254252.247.255.255131,070
125252.248.0.0/15252.248.0.1 to 252.249.255.254252.249.255.255131,070
126252.250.0.0/15252.250.0.1 to 252.251.255.254252.251.255.255131,070
127252.252.0.0/15252.252.0.1 to 252.253.255.254252.253.255.255131,070
128252.254.0.0/15252.254.0.1 to 252.255.255.254252.255.255.255131,070
129253.0.0.0/15253.0.0.1 to 253.1.255.254253.1.255.255131,070
130253.2.0.0/15253.2.0.1 to 253.3.255.254253.3.255.255131,070
131253.4.0.0/15253.4.0.1 to 253.5.255.254253.5.255.255131,070
132253.6.0.0/15253.6.0.1 to 253.7.255.254253.7.255.255131,070
133253.8.0.0/15253.8.0.1 to 253.9.255.254253.9.255.255131,070
134253.10.0.0/15253.10.0.1 to 253.11.255.254253.11.255.255131,070
135253.12.0.0/15253.12.0.1 to 253.13.255.254253.13.255.255131,070
136253.14.0.0/15253.14.0.1 to 253.15.255.254253.15.255.255131,070
137253.16.0.0/15253.16.0.1 to 253.17.255.254253.17.255.255131,070
138253.18.0.0/15253.18.0.1 to 253.19.255.254253.19.255.255131,070
139253.20.0.0/15253.20.0.1 to 253.21.255.254253.21.255.255131,070
140253.22.0.0/15253.22.0.1 to 253.23.255.254253.23.255.255131,070
141253.24.0.0/15253.24.0.1 to 253.25.255.254253.25.255.255131,070
142253.26.0.0/15253.26.0.1 to 253.27.255.254253.27.255.255131,070
143253.28.0.0/15253.28.0.1 to 253.29.255.254253.29.255.255131,070
144253.30.0.0/15253.30.0.1 to 253.31.255.254253.31.255.255131,070
145253.32.0.0/15253.32.0.1 to 253.33.255.254253.33.255.255131,070
146253.34.0.0/15253.34.0.1 to 253.35.255.254253.35.255.255131,070
147253.36.0.0/15253.36.0.1 to 253.37.255.254253.37.255.255131,070
148253.38.0.0/15253.38.0.1 to 253.39.255.254253.39.255.255131,070
149253.40.0.0/15253.40.0.1 to 253.41.255.254253.41.255.255131,070
150253.42.0.0/15253.42.0.1 to 253.43.255.254253.43.255.255131,070
151253.44.0.0/15253.44.0.1 to 253.45.255.254253.45.255.255131,070
152253.46.0.0/15253.46.0.1 to 253.47.255.254253.47.255.255131,070
153253.48.0.0/15253.48.0.1 to 253.49.255.254253.49.255.255131,070
154253.50.0.0/15253.50.0.1 to 253.51.255.254253.51.255.255131,070
155253.52.0.0/15253.52.0.1 to 253.53.255.254253.53.255.255131,070
156253.54.0.0/15253.54.0.1 to 253.55.255.254253.55.255.255131,070
157253.56.0.0/15253.56.0.1 to 253.57.255.254253.57.255.255131,070
158253.58.0.0/15253.58.0.1 to 253.59.255.254253.59.255.255131,070
159253.60.0.0/15253.60.0.1 to 253.61.255.254253.61.255.255131,070
160253.62.0.0/15253.62.0.1 to 253.63.255.254253.63.255.255131,070
161253.64.0.0/15253.64.0.1 to 253.65.255.254253.65.255.255131,070
162253.66.0.0/15253.66.0.1 to 253.67.255.254253.67.255.255131,070
163253.68.0.0/15253.68.0.1 to 253.69.255.254253.69.255.255131,070
164253.70.0.0/15253.70.0.1 to 253.71.255.254253.71.255.255131,070
165253.72.0.0/15253.72.0.1 to 253.73.255.254253.73.255.255131,070
166253.74.0.0/15253.74.0.1 to 253.75.255.254253.75.255.255131,070
167253.76.0.0/15253.76.0.1 to 253.77.255.254253.77.255.255131,070
168253.78.0.0/15253.78.0.1 to 253.79.255.254253.79.255.255131,070
169253.80.0.0/15253.80.0.1 to 253.81.255.254253.81.255.255131,070
170253.82.0.0/15253.82.0.1 to 253.83.255.254253.83.255.255131,070
171253.84.0.0/15253.84.0.1 to 253.85.255.254253.85.255.255131,070
172253.86.0.0/15253.86.0.1 to 253.87.255.254253.87.255.255131,070
173253.88.0.0/15253.88.0.1 to 253.89.255.254253.89.255.255131,070
174253.90.0.0/15253.90.0.1 to 253.91.255.254253.91.255.255131,070
175253.92.0.0/15253.92.0.1 to 253.93.255.254253.93.255.255131,070
176253.94.0.0/15253.94.0.1 to 253.95.255.254253.95.255.255131,070
177253.96.0.0/15253.96.0.1 to 253.97.255.254253.97.255.255131,070
178253.98.0.0/15253.98.0.1 to 253.99.255.254253.99.255.255131,070
179253.100.0.0/15253.100.0.1 to 253.101.255.254253.101.255.255131,070
180253.102.0.0/15253.102.0.1 to 253.103.255.254253.103.255.255131,070
181253.104.0.0/15253.104.0.1 to 253.105.255.254253.105.255.255131,070
182253.106.0.0/15253.106.0.1 to 253.107.255.254253.107.255.255131,070
183253.108.0.0/15253.108.0.1 to 253.109.255.254253.109.255.255131,070
184253.110.0.0/15253.110.0.1 to 253.111.255.254253.111.255.255131,070
185253.112.0.0/15253.112.0.1 to 253.113.255.254253.113.255.255131,070
186253.114.0.0/15253.114.0.1 to 253.115.255.254253.115.255.255131,070
187253.116.0.0/15253.116.0.1 to 253.117.255.254253.117.255.255131,070
188253.118.0.0/15253.118.0.1 to 253.119.255.254253.119.255.255131,070
189253.120.0.0/15253.120.0.1 to 253.121.255.254253.121.255.255131,070
190253.122.0.0/15253.122.0.1 to 253.123.255.254253.123.255.255131,070
191253.124.0.0/15253.124.0.1 to 253.125.255.254253.125.255.255131,070
192253.126.0.0/15253.126.0.1 to 253.127.255.254253.127.255.255131,070
193253.128.0.0/15253.128.0.1 to 253.129.255.254253.129.255.255131,070
194253.130.0.0/15253.130.0.1 to 253.131.255.254253.131.255.255131,070
195253.132.0.0/15253.132.0.1 to 253.133.255.254253.133.255.255131,070
196253.134.0.0/15253.134.0.1 to 253.135.255.254253.135.255.255131,070
197253.136.0.0/15253.136.0.1 to 253.137.255.254253.137.255.255131,070
198253.138.0.0/15253.138.0.1 to 253.139.255.254253.139.255.255131,070
199253.140.0.0/15253.140.0.1 to 253.141.255.254253.141.255.255131,070
200253.142.0.0/15253.142.0.1 to 253.143.255.254253.143.255.255131,070
201253.144.0.0/15253.144.0.1 to 253.145.255.254253.145.255.255131,070
202253.146.0.0/15253.146.0.1 to 253.147.255.254253.147.255.255131,070
203253.148.0.0/15253.148.0.1 to 253.149.255.254253.149.255.255131,070
204253.150.0.0/15253.150.0.1 to 253.151.255.254253.151.255.255131,070
205253.152.0.0/15253.152.0.1 to 253.153.255.254253.153.255.255131,070
206253.154.0.0/15253.154.0.1 to 253.155.255.254253.155.255.255131,070
207253.156.0.0/15253.156.0.1 to 253.157.255.254253.157.255.255131,070
208253.158.0.0/15253.158.0.1 to 253.159.255.254253.159.255.255131,070
209253.160.0.0/15253.160.0.1 to 253.161.255.254253.161.255.255131,070
210253.162.0.0/15253.162.0.1 to 253.163.255.254253.163.255.255131,070
211253.164.0.0/15253.164.0.1 to 253.165.255.254253.165.255.255131,070
212253.166.0.0/15253.166.0.1 to 253.167.255.254253.167.255.255131,070
213253.168.0.0/15253.168.0.1 to 253.169.255.254253.169.255.255131,070
214253.170.0.0/15253.170.0.1 to 253.171.255.254253.171.255.255131,070
215253.172.0.0/15253.172.0.1 to 253.173.255.254253.173.255.255131,070
216253.174.0.0/15253.174.0.1 to 253.175.255.254253.175.255.255131,070
217253.176.0.0/15253.176.0.1 to 253.177.255.254253.177.255.255131,070
218253.178.0.0/15253.178.0.1 to 253.179.255.254253.179.255.255131,070
219253.180.0.0/15253.180.0.1 to 253.181.255.254253.181.255.255131,070
220253.182.0.0/15253.182.0.1 to 253.183.255.254253.183.255.255131,070
221253.184.0.0/15253.184.0.1 to 253.185.255.254253.185.255.255131,070
222253.186.0.0/15253.186.0.1 to 253.187.255.254253.187.255.255131,070
223253.188.0.0/15253.188.0.1 to 253.189.255.254253.189.255.255131,070
224253.190.0.0/15253.190.0.1 to 253.191.255.254253.191.255.255131,070
225253.192.0.0/15253.192.0.1 to 253.193.255.254253.193.255.255131,070
226253.194.0.0/15253.194.0.1 to 253.195.255.254253.195.255.255131,070
227253.196.0.0/15253.196.0.1 to 253.197.255.254253.197.255.255131,070
228253.198.0.0/15253.198.0.1 to 253.199.255.254253.199.255.255131,070
229253.200.0.0/15253.200.0.1 to 253.201.255.254253.201.255.255131,070
230253.202.0.0/15253.202.0.1 to 253.203.255.254253.203.255.255131,070
231253.204.0.0/15253.204.0.1 to 253.205.255.254253.205.255.255131,070
232253.206.0.0/15253.206.0.1 to 253.207.255.254253.207.255.255131,070
233253.208.0.0/15253.208.0.1 to 253.209.255.254253.209.255.255131,070
234253.210.0.0/15253.210.0.1 to 253.211.255.254253.211.255.255131,070
235253.212.0.0/15253.212.0.1 to 253.213.255.254253.213.255.255131,070
236253.214.0.0/15253.214.0.1 to 253.215.255.254253.215.255.255131,070
237253.216.0.0/15253.216.0.1 to 253.217.255.254253.217.255.255131,070
238253.218.0.0/15253.218.0.1 to 253.219.255.254253.219.255.255131,070
239253.220.0.0/15253.220.0.1 to 253.221.255.254253.221.255.255131,070
240253.222.0.0/15253.222.0.1 to 253.223.255.254253.223.255.255131,070
241253.224.0.0/15253.224.0.1 to 253.225.255.254253.225.255.255131,070
242253.226.0.0/15253.226.0.1 to 253.227.255.254253.227.255.255131,070
243253.228.0.0/15253.228.0.1 to 253.229.255.254253.229.255.255131,070
244253.230.0.0/15253.230.0.1 to 253.231.255.254253.231.255.255131,070
245253.232.0.0/15253.232.0.1 to 253.233.255.254253.233.255.255131,070
246253.234.0.0/15253.234.0.1 to 253.235.255.254253.235.255.255131,070
247253.236.0.0/15253.236.0.1 to 253.237.255.254253.237.255.255131,070
248253.238.0.0/15253.238.0.1 to 253.239.255.254253.239.255.255131,070
249253.240.0.0/15253.240.0.1 to 253.241.255.254253.241.255.255131,070
250253.242.0.0/15253.242.0.1 to 253.243.255.254253.243.255.255131,070
251253.244.0.0/15253.244.0.1 to 253.245.255.254253.245.255.255131,070
252253.246.0.0/15253.246.0.1 to 253.247.255.254253.247.255.255131,070
253253.248.0.0/15253.248.0.1 to 253.249.255.254253.249.255.255131,070
254253.250.0.0/15253.250.0.1 to 253.251.255.254253.251.255.255131,070
255253.252.0.0/15253.252.0.1 to 253.253.255.254253.253.255.255131,070
256253.254.0.0/15253.254.0.1 to 253.255.255.254253.255.255.255131,070

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.