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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.

Network136.0.0.0/7
Usable hosts33,554,430
Subnet mask254.0.0.0
Addresses33,554,432
Network address
136.0.0.0
Broadcast address
137.255.255.255
First usable
136.0.0.1
Last usable
137.255.255.254
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
Public public
Old class
B (default /16)
As numbers
Hex 88000000 · Integer 2281701376 to 2315255807
Reverse DNS zones
136.in-addr.arpa
137.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
Address10001000.00000000.00000000.00000000136.0.0.0
Subnet mask11111110.00000000.00000000.00000000254.0.0.0
Network10001000.00000000.00000000.00000000136.0.0.0
Broadcast10001001.11111111.11111111.11111111137.255.255.255
Split into smaller subnets/16
/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)

136.0.0.0/7 makes 512 subnets of /16; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
1136.0.0.0/16136.0.0.1 to 136.0.255.254136.0.255.25565,534
2136.1.0.0/16136.1.0.1 to 136.1.255.254136.1.255.25565,534
3136.2.0.0/16136.2.0.1 to 136.2.255.254136.2.255.25565,534
4136.3.0.0/16136.3.0.1 to 136.3.255.254136.3.255.25565,534
5136.4.0.0/16136.4.0.1 to 136.4.255.254136.4.255.25565,534
6136.5.0.0/16136.5.0.1 to 136.5.255.254136.5.255.25565,534
7136.6.0.0/16136.6.0.1 to 136.6.255.254136.6.255.25565,534
8136.7.0.0/16136.7.0.1 to 136.7.255.254136.7.255.25565,534
9136.8.0.0/16136.8.0.1 to 136.8.255.254136.8.255.25565,534
10136.9.0.0/16136.9.0.1 to 136.9.255.254136.9.255.25565,534
11136.10.0.0/16136.10.0.1 to 136.10.255.254136.10.255.25565,534
12136.11.0.0/16136.11.0.1 to 136.11.255.254136.11.255.25565,534
13136.12.0.0/16136.12.0.1 to 136.12.255.254136.12.255.25565,534
14136.13.0.0/16136.13.0.1 to 136.13.255.254136.13.255.25565,534
15136.14.0.0/16136.14.0.1 to 136.14.255.254136.14.255.25565,534
16136.15.0.0/16136.15.0.1 to 136.15.255.254136.15.255.25565,534
17136.16.0.0/16136.16.0.1 to 136.16.255.254136.16.255.25565,534
18136.17.0.0/16136.17.0.1 to 136.17.255.254136.17.255.25565,534
19136.18.0.0/16136.18.0.1 to 136.18.255.254136.18.255.25565,534
20136.19.0.0/16136.19.0.1 to 136.19.255.254136.19.255.25565,534
21136.20.0.0/16136.20.0.1 to 136.20.255.254136.20.255.25565,534
22136.21.0.0/16136.21.0.1 to 136.21.255.254136.21.255.25565,534
23136.22.0.0/16136.22.0.1 to 136.22.255.254136.22.255.25565,534
24136.23.0.0/16136.23.0.1 to 136.23.255.254136.23.255.25565,534
25136.24.0.0/16136.24.0.1 to 136.24.255.254136.24.255.25565,534
26136.25.0.0/16136.25.0.1 to 136.25.255.254136.25.255.25565,534
27136.26.0.0/16136.26.0.1 to 136.26.255.254136.26.255.25565,534
28136.27.0.0/16136.27.0.1 to 136.27.255.254136.27.255.25565,534
29136.28.0.0/16136.28.0.1 to 136.28.255.254136.28.255.25565,534
30136.29.0.0/16136.29.0.1 to 136.29.255.254136.29.255.25565,534
31136.30.0.0/16136.30.0.1 to 136.30.255.254136.30.255.25565,534
32136.31.0.0/16136.31.0.1 to 136.31.255.254136.31.255.25565,534
33136.32.0.0/16136.32.0.1 to 136.32.255.254136.32.255.25565,534
34136.33.0.0/16136.33.0.1 to 136.33.255.254136.33.255.25565,534
35136.34.0.0/16136.34.0.1 to 136.34.255.254136.34.255.25565,534
36136.35.0.0/16136.35.0.1 to 136.35.255.254136.35.255.25565,534
37136.36.0.0/16136.36.0.1 to 136.36.255.254136.36.255.25565,534
38136.37.0.0/16136.37.0.1 to 136.37.255.254136.37.255.25565,534
39136.38.0.0/16136.38.0.1 to 136.38.255.254136.38.255.25565,534
40136.39.0.0/16136.39.0.1 to 136.39.255.254136.39.255.25565,534
41136.40.0.0/16136.40.0.1 to 136.40.255.254136.40.255.25565,534
42136.41.0.0/16136.41.0.1 to 136.41.255.254136.41.255.25565,534
43136.42.0.0/16136.42.0.1 to 136.42.255.254136.42.255.25565,534
44136.43.0.0/16136.43.0.1 to 136.43.255.254136.43.255.25565,534
45136.44.0.0/16136.44.0.1 to 136.44.255.254136.44.255.25565,534
46136.45.0.0/16136.45.0.1 to 136.45.255.254136.45.255.25565,534
47136.46.0.0/16136.46.0.1 to 136.46.255.254136.46.255.25565,534
48136.47.0.0/16136.47.0.1 to 136.47.255.254136.47.255.25565,534
49136.48.0.0/16136.48.0.1 to 136.48.255.254136.48.255.25565,534
50136.49.0.0/16136.49.0.1 to 136.49.255.254136.49.255.25565,534
51136.50.0.0/16136.50.0.1 to 136.50.255.254136.50.255.25565,534
52136.51.0.0/16136.51.0.1 to 136.51.255.254136.51.255.25565,534
53136.52.0.0/16136.52.0.1 to 136.52.255.254136.52.255.25565,534
54136.53.0.0/16136.53.0.1 to 136.53.255.254136.53.255.25565,534
55136.54.0.0/16136.54.0.1 to 136.54.255.254136.54.255.25565,534
56136.55.0.0/16136.55.0.1 to 136.55.255.254136.55.255.25565,534
57136.56.0.0/16136.56.0.1 to 136.56.255.254136.56.255.25565,534
58136.57.0.0/16136.57.0.1 to 136.57.255.254136.57.255.25565,534
59136.58.0.0/16136.58.0.1 to 136.58.255.254136.58.255.25565,534
60136.59.0.0/16136.59.0.1 to 136.59.255.254136.59.255.25565,534
61136.60.0.0/16136.60.0.1 to 136.60.255.254136.60.255.25565,534
62136.61.0.0/16136.61.0.1 to 136.61.255.254136.61.255.25565,534
63136.62.0.0/16136.62.0.1 to 136.62.255.254136.62.255.25565,534
64136.63.0.0/16136.63.0.1 to 136.63.255.254136.63.255.25565,534
65136.64.0.0/16136.64.0.1 to 136.64.255.254136.64.255.25565,534
66136.65.0.0/16136.65.0.1 to 136.65.255.254136.65.255.25565,534
67136.66.0.0/16136.66.0.1 to 136.66.255.254136.66.255.25565,534
68136.67.0.0/16136.67.0.1 to 136.67.255.254136.67.255.25565,534
69136.68.0.0/16136.68.0.1 to 136.68.255.254136.68.255.25565,534
70136.69.0.0/16136.69.0.1 to 136.69.255.254136.69.255.25565,534
71136.70.0.0/16136.70.0.1 to 136.70.255.254136.70.255.25565,534
72136.71.0.0/16136.71.0.1 to 136.71.255.254136.71.255.25565,534
73136.72.0.0/16136.72.0.1 to 136.72.255.254136.72.255.25565,534
74136.73.0.0/16136.73.0.1 to 136.73.255.254136.73.255.25565,534
75136.74.0.0/16136.74.0.1 to 136.74.255.254136.74.255.25565,534
76136.75.0.0/16136.75.0.1 to 136.75.255.254136.75.255.25565,534
77136.76.0.0/16136.76.0.1 to 136.76.255.254136.76.255.25565,534
78136.77.0.0/16136.77.0.1 to 136.77.255.254136.77.255.25565,534
79136.78.0.0/16136.78.0.1 to 136.78.255.254136.78.255.25565,534
80136.79.0.0/16136.79.0.1 to 136.79.255.254136.79.255.25565,534
81136.80.0.0/16136.80.0.1 to 136.80.255.254136.80.255.25565,534
82136.81.0.0/16136.81.0.1 to 136.81.255.254136.81.255.25565,534
83136.82.0.0/16136.82.0.1 to 136.82.255.254136.82.255.25565,534
84136.83.0.0/16136.83.0.1 to 136.83.255.254136.83.255.25565,534
85136.84.0.0/16136.84.0.1 to 136.84.255.254136.84.255.25565,534
86136.85.0.0/16136.85.0.1 to 136.85.255.254136.85.255.25565,534
87136.86.0.0/16136.86.0.1 to 136.86.255.254136.86.255.25565,534
88136.87.0.0/16136.87.0.1 to 136.87.255.254136.87.255.25565,534
89136.88.0.0/16136.88.0.1 to 136.88.255.254136.88.255.25565,534
90136.89.0.0/16136.89.0.1 to 136.89.255.254136.89.255.25565,534
91136.90.0.0/16136.90.0.1 to 136.90.255.254136.90.255.25565,534
92136.91.0.0/16136.91.0.1 to 136.91.255.254136.91.255.25565,534
93136.92.0.0/16136.92.0.1 to 136.92.255.254136.92.255.25565,534
94136.93.0.0/16136.93.0.1 to 136.93.255.254136.93.255.25565,534
95136.94.0.0/16136.94.0.1 to 136.94.255.254136.94.255.25565,534
96136.95.0.0/16136.95.0.1 to 136.95.255.254136.95.255.25565,534
97136.96.0.0/16136.96.0.1 to 136.96.255.254136.96.255.25565,534
98136.97.0.0/16136.97.0.1 to 136.97.255.254136.97.255.25565,534
99136.98.0.0/16136.98.0.1 to 136.98.255.254136.98.255.25565,534
100136.99.0.0/16136.99.0.1 to 136.99.255.254136.99.255.25565,534
101136.100.0.0/16136.100.0.1 to 136.100.255.254136.100.255.25565,534
102136.101.0.0/16136.101.0.1 to 136.101.255.254136.101.255.25565,534
103136.102.0.0/16136.102.0.1 to 136.102.255.254136.102.255.25565,534
104136.103.0.0/16136.103.0.1 to 136.103.255.254136.103.255.25565,534
105136.104.0.0/16136.104.0.1 to 136.104.255.254136.104.255.25565,534
106136.105.0.0/16136.105.0.1 to 136.105.255.254136.105.255.25565,534
107136.106.0.0/16136.106.0.1 to 136.106.255.254136.106.255.25565,534
108136.107.0.0/16136.107.0.1 to 136.107.255.254136.107.255.25565,534
109136.108.0.0/16136.108.0.1 to 136.108.255.254136.108.255.25565,534
110136.109.0.0/16136.109.0.1 to 136.109.255.254136.109.255.25565,534
111136.110.0.0/16136.110.0.1 to 136.110.255.254136.110.255.25565,534
112136.111.0.0/16136.111.0.1 to 136.111.255.254136.111.255.25565,534
113136.112.0.0/16136.112.0.1 to 136.112.255.254136.112.255.25565,534
114136.113.0.0/16136.113.0.1 to 136.113.255.254136.113.255.25565,534
115136.114.0.0/16136.114.0.1 to 136.114.255.254136.114.255.25565,534
116136.115.0.0/16136.115.0.1 to 136.115.255.254136.115.255.25565,534
117136.116.0.0/16136.116.0.1 to 136.116.255.254136.116.255.25565,534
118136.117.0.0/16136.117.0.1 to 136.117.255.254136.117.255.25565,534
119136.118.0.0/16136.118.0.1 to 136.118.255.254136.118.255.25565,534
120136.119.0.0/16136.119.0.1 to 136.119.255.254136.119.255.25565,534
121136.120.0.0/16136.120.0.1 to 136.120.255.254136.120.255.25565,534
122136.121.0.0/16136.121.0.1 to 136.121.255.254136.121.255.25565,534
123136.122.0.0/16136.122.0.1 to 136.122.255.254136.122.255.25565,534
124136.123.0.0/16136.123.0.1 to 136.123.255.254136.123.255.25565,534
125136.124.0.0/16136.124.0.1 to 136.124.255.254136.124.255.25565,534
126136.125.0.0/16136.125.0.1 to 136.125.255.254136.125.255.25565,534
127136.126.0.0/16136.126.0.1 to 136.126.255.254136.126.255.25565,534
128136.127.0.0/16136.127.0.1 to 136.127.255.254136.127.255.25565,534
129136.128.0.0/16136.128.0.1 to 136.128.255.254136.128.255.25565,534
130136.129.0.0/16136.129.0.1 to 136.129.255.254136.129.255.25565,534
131136.130.0.0/16136.130.0.1 to 136.130.255.254136.130.255.25565,534
132136.131.0.0/16136.131.0.1 to 136.131.255.254136.131.255.25565,534
133136.132.0.0/16136.132.0.1 to 136.132.255.254136.132.255.25565,534
134136.133.0.0/16136.133.0.1 to 136.133.255.254136.133.255.25565,534
135136.134.0.0/16136.134.0.1 to 136.134.255.254136.134.255.25565,534
136136.135.0.0/16136.135.0.1 to 136.135.255.254136.135.255.25565,534
137136.136.0.0/16136.136.0.1 to 136.136.255.254136.136.255.25565,534
138136.137.0.0/16136.137.0.1 to 136.137.255.254136.137.255.25565,534
139136.138.0.0/16136.138.0.1 to 136.138.255.254136.138.255.25565,534
140136.139.0.0/16136.139.0.1 to 136.139.255.254136.139.255.25565,534
141136.140.0.0/16136.140.0.1 to 136.140.255.254136.140.255.25565,534
142136.141.0.0/16136.141.0.1 to 136.141.255.254136.141.255.25565,534
143136.142.0.0/16136.142.0.1 to 136.142.255.254136.142.255.25565,534
144136.143.0.0/16136.143.0.1 to 136.143.255.254136.143.255.25565,534
145136.144.0.0/16136.144.0.1 to 136.144.255.254136.144.255.25565,534
146136.145.0.0/16136.145.0.1 to 136.145.255.254136.145.255.25565,534
147136.146.0.0/16136.146.0.1 to 136.146.255.254136.146.255.25565,534
148136.147.0.0/16136.147.0.1 to 136.147.255.254136.147.255.25565,534
149136.148.0.0/16136.148.0.1 to 136.148.255.254136.148.255.25565,534
150136.149.0.0/16136.149.0.1 to 136.149.255.254136.149.255.25565,534
151136.150.0.0/16136.150.0.1 to 136.150.255.254136.150.255.25565,534
152136.151.0.0/16136.151.0.1 to 136.151.255.254136.151.255.25565,534
153136.152.0.0/16136.152.0.1 to 136.152.255.254136.152.255.25565,534
154136.153.0.0/16136.153.0.1 to 136.153.255.254136.153.255.25565,534
155136.154.0.0/16136.154.0.1 to 136.154.255.254136.154.255.25565,534
156136.155.0.0/16136.155.0.1 to 136.155.255.254136.155.255.25565,534
157136.156.0.0/16136.156.0.1 to 136.156.255.254136.156.255.25565,534
158136.157.0.0/16136.157.0.1 to 136.157.255.254136.157.255.25565,534
159136.158.0.0/16136.158.0.1 to 136.158.255.254136.158.255.25565,534
160136.159.0.0/16136.159.0.1 to 136.159.255.254136.159.255.25565,534
161136.160.0.0/16136.160.0.1 to 136.160.255.254136.160.255.25565,534
162136.161.0.0/16136.161.0.1 to 136.161.255.254136.161.255.25565,534
163136.162.0.0/16136.162.0.1 to 136.162.255.254136.162.255.25565,534
164136.163.0.0/16136.163.0.1 to 136.163.255.254136.163.255.25565,534
165136.164.0.0/16136.164.0.1 to 136.164.255.254136.164.255.25565,534
166136.165.0.0/16136.165.0.1 to 136.165.255.254136.165.255.25565,534
167136.166.0.0/16136.166.0.1 to 136.166.255.254136.166.255.25565,534
168136.167.0.0/16136.167.0.1 to 136.167.255.254136.167.255.25565,534
169136.168.0.0/16136.168.0.1 to 136.168.255.254136.168.255.25565,534
170136.169.0.0/16136.169.0.1 to 136.169.255.254136.169.255.25565,534
171136.170.0.0/16136.170.0.1 to 136.170.255.254136.170.255.25565,534
172136.171.0.0/16136.171.0.1 to 136.171.255.254136.171.255.25565,534
173136.172.0.0/16136.172.0.1 to 136.172.255.254136.172.255.25565,534
174136.173.0.0/16136.173.0.1 to 136.173.255.254136.173.255.25565,534
175136.174.0.0/16136.174.0.1 to 136.174.255.254136.174.255.25565,534
176136.175.0.0/16136.175.0.1 to 136.175.255.254136.175.255.25565,534
177136.176.0.0/16136.176.0.1 to 136.176.255.254136.176.255.25565,534
178136.177.0.0/16136.177.0.1 to 136.177.255.254136.177.255.25565,534
179136.178.0.0/16136.178.0.1 to 136.178.255.254136.178.255.25565,534
180136.179.0.0/16136.179.0.1 to 136.179.255.254136.179.255.25565,534
181136.180.0.0/16136.180.0.1 to 136.180.255.254136.180.255.25565,534
182136.181.0.0/16136.181.0.1 to 136.181.255.254136.181.255.25565,534
183136.182.0.0/16136.182.0.1 to 136.182.255.254136.182.255.25565,534
184136.183.0.0/16136.183.0.1 to 136.183.255.254136.183.255.25565,534
185136.184.0.0/16136.184.0.1 to 136.184.255.254136.184.255.25565,534
186136.185.0.0/16136.185.0.1 to 136.185.255.254136.185.255.25565,534
187136.186.0.0/16136.186.0.1 to 136.186.255.254136.186.255.25565,534
188136.187.0.0/16136.187.0.1 to 136.187.255.254136.187.255.25565,534
189136.188.0.0/16136.188.0.1 to 136.188.255.254136.188.255.25565,534
190136.189.0.0/16136.189.0.1 to 136.189.255.254136.189.255.25565,534
191136.190.0.0/16136.190.0.1 to 136.190.255.254136.190.255.25565,534
192136.191.0.0/16136.191.0.1 to 136.191.255.254136.191.255.25565,534
193136.192.0.0/16136.192.0.1 to 136.192.255.254136.192.255.25565,534
194136.193.0.0/16136.193.0.1 to 136.193.255.254136.193.255.25565,534
195136.194.0.0/16136.194.0.1 to 136.194.255.254136.194.255.25565,534
196136.195.0.0/16136.195.0.1 to 136.195.255.254136.195.255.25565,534
197136.196.0.0/16136.196.0.1 to 136.196.255.254136.196.255.25565,534
198136.197.0.0/16136.197.0.1 to 136.197.255.254136.197.255.25565,534
199136.198.0.0/16136.198.0.1 to 136.198.255.254136.198.255.25565,534
200136.199.0.0/16136.199.0.1 to 136.199.255.254136.199.255.25565,534
201136.200.0.0/16136.200.0.1 to 136.200.255.254136.200.255.25565,534
202136.201.0.0/16136.201.0.1 to 136.201.255.254136.201.255.25565,534
203136.202.0.0/16136.202.0.1 to 136.202.255.254136.202.255.25565,534
204136.203.0.0/16136.203.0.1 to 136.203.255.254136.203.255.25565,534
205136.204.0.0/16136.204.0.1 to 136.204.255.254136.204.255.25565,534
206136.205.0.0/16136.205.0.1 to 136.205.255.254136.205.255.25565,534
207136.206.0.0/16136.206.0.1 to 136.206.255.254136.206.255.25565,534
208136.207.0.0/16136.207.0.1 to 136.207.255.254136.207.255.25565,534
209136.208.0.0/16136.208.0.1 to 136.208.255.254136.208.255.25565,534
210136.209.0.0/16136.209.0.1 to 136.209.255.254136.209.255.25565,534
211136.210.0.0/16136.210.0.1 to 136.210.255.254136.210.255.25565,534
212136.211.0.0/16136.211.0.1 to 136.211.255.254136.211.255.25565,534
213136.212.0.0/16136.212.0.1 to 136.212.255.254136.212.255.25565,534
214136.213.0.0/16136.213.0.1 to 136.213.255.254136.213.255.25565,534
215136.214.0.0/16136.214.0.1 to 136.214.255.254136.214.255.25565,534
216136.215.0.0/16136.215.0.1 to 136.215.255.254136.215.255.25565,534
217136.216.0.0/16136.216.0.1 to 136.216.255.254136.216.255.25565,534
218136.217.0.0/16136.217.0.1 to 136.217.255.254136.217.255.25565,534
219136.218.0.0/16136.218.0.1 to 136.218.255.254136.218.255.25565,534
220136.219.0.0/16136.219.0.1 to 136.219.255.254136.219.255.25565,534
221136.220.0.0/16136.220.0.1 to 136.220.255.254136.220.255.25565,534
222136.221.0.0/16136.221.0.1 to 136.221.255.254136.221.255.25565,534
223136.222.0.0/16136.222.0.1 to 136.222.255.254136.222.255.25565,534
224136.223.0.0/16136.223.0.1 to 136.223.255.254136.223.255.25565,534
225136.224.0.0/16136.224.0.1 to 136.224.255.254136.224.255.25565,534
226136.225.0.0/16136.225.0.1 to 136.225.255.254136.225.255.25565,534
227136.226.0.0/16136.226.0.1 to 136.226.255.254136.226.255.25565,534
228136.227.0.0/16136.227.0.1 to 136.227.255.254136.227.255.25565,534
229136.228.0.0/16136.228.0.1 to 136.228.255.254136.228.255.25565,534
230136.229.0.0/16136.229.0.1 to 136.229.255.254136.229.255.25565,534
231136.230.0.0/16136.230.0.1 to 136.230.255.254136.230.255.25565,534
232136.231.0.0/16136.231.0.1 to 136.231.255.254136.231.255.25565,534
233136.232.0.0/16136.232.0.1 to 136.232.255.254136.232.255.25565,534
234136.233.0.0/16136.233.0.1 to 136.233.255.254136.233.255.25565,534
235136.234.0.0/16136.234.0.1 to 136.234.255.254136.234.255.25565,534
236136.235.0.0/16136.235.0.1 to 136.235.255.254136.235.255.25565,534
237136.236.0.0/16136.236.0.1 to 136.236.255.254136.236.255.25565,534
238136.237.0.0/16136.237.0.1 to 136.237.255.254136.237.255.25565,534
239136.238.0.0/16136.238.0.1 to 136.238.255.254136.238.255.25565,534
240136.239.0.0/16136.239.0.1 to 136.239.255.254136.239.255.25565,534
241136.240.0.0/16136.240.0.1 to 136.240.255.254136.240.255.25565,534
242136.241.0.0/16136.241.0.1 to 136.241.255.254136.241.255.25565,534
243136.242.0.0/16136.242.0.1 to 136.242.255.254136.242.255.25565,534
244136.243.0.0/16136.243.0.1 to 136.243.255.254136.243.255.25565,534
245136.244.0.0/16136.244.0.1 to 136.244.255.254136.244.255.25565,534
246136.245.0.0/16136.245.0.1 to 136.245.255.254136.245.255.25565,534
247136.246.0.0/16136.246.0.1 to 136.246.255.254136.246.255.25565,534
248136.247.0.0/16136.247.0.1 to 136.247.255.254136.247.255.25565,534
249136.248.0.0/16136.248.0.1 to 136.248.255.254136.248.255.25565,534
250136.249.0.0/16136.249.0.1 to 136.249.255.254136.249.255.25565,534
251136.250.0.0/16136.250.0.1 to 136.250.255.254136.250.255.25565,534
252136.251.0.0/16136.251.0.1 to 136.251.255.254136.251.255.25565,534
253136.252.0.0/16136.252.0.1 to 136.252.255.254136.252.255.25565,534
254136.253.0.0/16136.253.0.1 to 136.253.255.254136.253.255.25565,534
255136.254.0.0/16136.254.0.1 to 136.254.255.254136.254.255.25565,534
256136.255.0.0/16136.255.0.1 to 136.255.255.254136.255.255.25565,534

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.